List of Ben 10 characters

This is a list of characters in the universe of the Ben 10 franchise ranging from Ben 10, Ben 10: Alien Force, and Ben 10: Ultimate Alien.

Ben Tennyson

 * Tara Strong - Ben 10 and Ben 10: Ultimate Alien (4 years in "Don't Drink The Water" and 10 year old)
 * Fred Tatasciore - Ben 10 (Ben 10,000 30 years old)
 * Graham Phillips - Ben 10: Race Against Time
 * Yuri Lowenthal - Ben 10: Alien Force and Ben 10: Ultimate Alien (15 and 16 year old)
 * Ryan Kelley - Ben 10: Alien Swarm
 * John DiMaggio - Ben 10: Ultimate Alien (Ben 10,000 from the cross-time 36 years old)

Benjamin "Ben" Kirby Tennyson, also known as Ben 10, is the main protagonist of the series. When he is 10 years old (fifteen in Alien Force, sixteen in Ultimate Alien), he finds a powerful watch-like alien device, the Omnitrix, which fastens onto his wrist and gives him the incredible power and ability to transform into ten (later more) super-powered aliens. Unable to remove or destroy it, he uses his new powers and abilities to become a superhero, dealing with both aliens and earth threats, while trying to escape the alien warlord Vilgax, who pursue him relentlessly in order to retrieve the Omnitrix.

For most of the series, Ben is portrayed as an immature, sometimes self-centered boy; in the beginning, he only helped people the pleasure of being a hero. He has matured dramatically and is a very capable good leader in the five-year sequel Ben 10: Alien Force due to Grandpa Max's disappearance and the threat of the Highbreed Invasion, but tends to relax and (somewhat) turn back to his original self in the third season. He also had a complex love-hate relationship with his ten-year-old cousin Gwen in the original show. And since he was a kid, he always loved the "Sumo Slammers", and has a tendency to say Oh, man, and  It's hero time.

Despite his immaturity, Ben's actions are motivated above all by a strong and sincere will to help other people; he'll stop at nothing to protect his family or anyone in danger. Sometimes, his idealistic nature tends to make him act naive.

Though often thought by many other characters to be quite unintelligent, Ben actually proves to be resourceful and cunning when needed. When he toned down his immaturity in the first 2 seasons of Ben 10: Alien Force, he proved to be a capable leader for his team, although after his success at saving the universe from the Highbreed Invasion, his overconfidence caused him to revert to his immature personality. In the episode "Where the Magic Happens", Kevin shows surprise when Ben is able to memorize a sentence of magic symbols with a mere look, hinting that he possesses a form of photographic memory. Gwen also states that he isn't working to his potential in school, to which he agrees. While attending the Plumber Academy in "Basic Training", Ben seemingly does not pay attention to his classes or the drill sergeant, yet still manages to achieve a grade of 95 upon completion of the course.How much of that is the previous training Ben received from his grandfather and his actions in the episode is unknown.

Ben, like cousins Gwen and Ken, father Carl and Uncle Frank, is of Anodite heritage, though he doesn't have his grandmother's spark like Gwen.

In the two-part series finale of the five-year sequel "Ben 10: Alien Force," Ben lost the Omnitrix to Vilgax and was later forced to sacrifice it by ordering it to self-destruct. He then successfully took from his evil twin Albedo the Ultimatrix, a more advanced version of the Omnitrix. In addition to the original Omnitrix shape shifting powers, the Ultimatrix gives Ben the power to make his aliens evolve into more powerful forms, called "Ultimate’s."

In "Ben 10: Alien Swarm", Kevin gives Ben a new car for his 16th birthday. Kevin says that he'll keep it (since Ben destroyed his own with Humongousaur), but Ben threatens to throw the new one if he can't keep it. Ben is seen frequently driving his new car, titled the "DX Mark 10" (shown as a Mazda RX-8 in "Alien Swarm") in "Ben 10: Ultimate Alien."

Ben's middle name is revealed to be "Kirby". This is proven by Gwen in "Duped". Named after the golden age comic book artist, Jack Kirby.

It is mentioned by Azmuth, who was told by Paradox, that Ben is a legendary being who would do something incredible someday, but Paradox has Azmuth keeping it a secret.

In the future, Ben has become a full-time hero, his identity is revealed since Ben 10: Ultimate Alien and is recognized everywhere as Ben 10,000, no matter what alien form he is using (obviously because he has an Omnitrix/Ultimatrix symbol on his chest in alien form). The name comes from the fact that now Ben has access to 10,000 alien forms, he also has unlocked the Omnitrix's master control function, allowing him to switch forms at will, without timing out. In "Ben 10,000", it showed how dark the future of Ben Tennyson could be. He has grown into a more strict and serious character, going so far as to stop naming his aliens (which the present Ben considers "half the fun" of using them), but through his interaction with his past self, it causes him to lighten up somewhat, naming his aliens all over again. In "Ben 10,000 Returns", Ben meets what is apparently his true future self (The one he met when he was ten is revealed to be from an alternate timeline). This version retains the present-day Ben's personality, and uses the Ultimate function on his human form, allowing him to access his aliens' powers without actually changing.

The 10 year old Ben is in the Ben 10: Ultimate Alien episode "The Forge Of Creation". He is helping the present day Ben. Tara Strong reprises her role as the Ben from the original series. This Ben looks slightly different from the original. He has different shoes and his face resembles 16 year old Ben's. Also, the plumber symbol on young Ben's aliens has a green tint rather than black and white in the original series.

Ben appears as the main character in all five video games based on the series, and also as an NPC in Cartoon Network Universe: FusionFall.

Gwen Tennyson

 * Meagan Smith - Ben 10 (10 years old)
 * Haley Ramm - Ben 10: Race Against Time
 * Ashley Johnson - Ben 10: Alien Force and Ben 10: Ultimate Alien (15 and 16 years old)
 * Tara Strong - Ben 10 (30 and 42 year old in "Ben 10,000" and "Ken 10")
 * Galadriel Stineman - Ben 10: Alien Swarm

Gwendolyn "Gwen" Tennyson is Ben's ten-year old cousin (fifteen in Alien Force, and sixteen in Ultimate Alien [the two share the same birthday]).

In the original series, Gwen shares a love-hate relationship with Ben, insulting him with dry wit and sarcasm most of the time, and like Ben, she was very immature, in part due to their shared birthday. She annoyed Ben a lot, prompting him to pick on her. She uses her laptop to research any strange people and/or creatures they might come across, is a capable gymnast, and has had some training in martial arts. She has also shown an almost innate skill in using various complicated devices or objects, such as in the non-canon episode "Gwen 10", when Gwen gained the Omnitrix instead of Ben and proved to be far more adept and responsible in its use than he initially was.

Overall, her most notable skill is her innate, if latent, power and ability at magic. Having within her what Charmcaster calls a magical aura (which is bright blue in the original series and shades of pink, magenta, fuchsia and varying shades of purple in Ben 10: Alien Force and Ben 10: Ultimate Alien), Gwen is capable of using various magical artifacts, charms, talismans, spell books and spells. When using the mystical and magical luck-giving Charm of Bezel, she was able to activate it instinctively, whereas Hex did or could not. Later on, when she takes and uses his staff, she was able to make it fire a light yellow-colored energy blast. According to Charmcaster, only someone of Hex's skill should have that power and ability. On two occasions, Gwen has the Charms of Bezel to become a superhero by the name of Lucky Girl. At first, her power and ability drew from the luck-granting Charm of Bezel, which innately gave her complete perfect luck. While wearing the charm, any action she took would result in a chain reaction benefiting her original intent, but usually injuring Ben in the process. She later brought back her superhero identity after obtaining the Keystone of Bezel, which greatly increased and strengthened her natural abilities to superhuman levels rather than just affecting her luck. Both times, Gwen was forced to retire when the Charms of Bezel were destroyed. However, in a twenty-year alternate future, thirty-year-old Gwen goes to the mystical interdimensional realm of Bezel to receive a new set of charms. For an unknown reason she does not have the Keystone of Bezel in her possession.

In Ben 10: Alien Force, her magical powers and abilities have greatly strengthened and increased to even higher power levels, and she is easily able to control and manipulate pure pink glowing energy from her magical aura to create energy blasts, shields, barriers, and other structures, like hammers, protective helmets, battering rams, beams to grab and hurl enemies, stepping stones to carry herself and others through the air, and safety nets; turns out that Gwen can also synchronize her martial arts styles with her mana manipulating abilities. It is also revealed that her paternal grandmother Verdona was an energy being known as an Anodite from the distant planet Anodyne, a free-spirited alien species who possess the exceedingly strong and powerful power and ability to manipulate and control a supernatural force-like substance called life energy most commonly known as mana (which can also be referred to either chakra or chi), the very source of magic itself, which explained Gwen's unusual affinity with magic. Gwen is also able to take on an Anodite energy form like her grandmother if she is under a great deal of stress. Also notable is that over the course of the later series, she has two character designs. Her blue dress was featured in the first two seasons of Ben 10: Alien Force, and then a later red-coloured redesign appearing in Ben 10: Alien Swarm when the gang goes to Missouri, later used in the third season of Ben 10: Alien Force, and recycled later on Ben 10: Ultimate Alien.

Gwen is shown to be very intelligent and knowledgeable. Before discovering her dormant innate magical and Anodite powers, she would often use her "brains" to help Ben. She is shown to be a bit of computer and tech wiz as well. She has her own laptop which she uses to research enemies she meets. She is straightforward and very brave despite the circumstances. Gwen is a very well student, especially in episode "It's Not Easy Being Gwen", where shows that Gwen takes her education very seriously. Showing to come home late at all hours of the morning and having to wake up at 5:30am in the morning, when waking up so early she does a number of things before going to school. Such as jogging, practice French, school, and afterschool karate classes. It’s also presumed that Gwen goes to private school since it shown that her usual clothing is actually a uniform at her school.

Gwen appears in all five video games based on the series, although she is only playable in "Ben 10: Protector of Earth" and "Ben 10 Alien Force: The Game". She also appears as an NPC in Cartoon Network Universe: FusionFall.

Grandpa Max Tennyson

 * Paul Eiding - Ben 10, Ben 10: Alien Force and Ben 10: Ultimate Alien (60, 65 and 66 years old)
 * Adam Wylie - Ben 10 (10 years old in "Don't Drink the Water")
 * Jason Marsden - Ben 10: Ultimate Alien (17 years old in "Moonstruck" flashback)
 * Lee Majors - Ben 10: Race Against Time
 * Barry Corbin - Ben 10: Alien Swarm

Maxwell "Max" Tennyson is a sixty-year old (sixty-five in Ben 10: Alien Force, sixty-six in Ben 10: Ultimate Alien), rather overweight and a bit slow at times, paternal grandfather of the cousins Ben and Gwen Tennyson. Despite his age, Max has shown on multiple occasions to be highly athletic and a formidable fighter. He takes his grandson gaining superpowers and super-abilities in stride and supports Ben in any way he can. Max was once in the United States Army, had been in a astronaut program, and was a "plumber" and has been through his share of scrapes. Ben and Gwen were ignorant of this at first, believing him to have been a literal plumber. They began questioning this after several incidents in which he displayed knowledge and skills that a plumber would not normally have; everything from military-style hand signals to a working knowledge of nuclear reactors. Throughout the first season, it seems that Max knows far more about aliens than he lets on, which climaxes in the season finale, where it is revealed that he and Vilgax are old enemies, with Vilgax even going so far as to call Max "a thorn in his side".

In reality, Max was indeed a plumber, but not the kind that Ben and Gwen thought he was. He was part of an interstellar policing counter-terrorist/black-ops organization called "The Plumbers", which dealt with extraterrestrial, paranormal, and other situations that many others could not handle. The group was disbanded shortly after Max defeated Vilgax for the first time, suggesting that Vilgax had been largely responsible for the various incidents they dealt with. Max was to have been among the candidates eligible for the Apollo 11 mission, and would have gone were it not for other concerns. Max is an old friend of an alien named Xylene. Xylene, like all the other three-eyed aliens of her planet, has the powers and abilities of flight, telepathy, and telekinesis. She had intended to send the Omnitrix to Max, but Ben found it by accident. Max and Xylene seem to have been romantically involved and work well as a team. Xylene tries to convince Max to form a partnership and travel across the galaxy with her, but Max eventually turns her down twice: the first time due to his duties as a Plumber, and the second time due to his need to look after the kids.

He also had a romantic relationship with an Anodite alien named Verdona. They ended up having two sons, Carl Tennyson, Ben's father, and Frank Tennyson, Gwen and Ken's father. However it seems that their relationship had apparently ended as Verdona left Earth to return to her home planet, Anodyne. She was assumed dead by her husband in "Ben 10: Race Against Time".

In Ben 10: Alien Force, Max plays a part in exposing the Highbreed conspiracy, and once the conflict is over, trains a new group of young Plumbers, at the same time informing Ben and the team of any alien threats.

In Ben 10: Ultimate Alien, at age sixty-six, Max continues to watch for alien attacks. During an encounter with Aggregor in "Map of Infinity", his nervous system is badly damaged. Azmuth has him placed in a Galvan medical tank in order to replace the damaged parts, an operation that is stated to take some time. However, he returns in the two-part season one finale "Absolute Power", his nervous system having been fully restored, and assists his two grandchildren in battling the villainous, Ultimate Kevin.

In the Ben 10 video game series, Grandpa Max only appears in "Ben 10: Protector of Earth", and "Ben 10 Alien Force: Vilgax Attacks". He plays a bigger role in the later game, guiding Ben to the locations of power sources Vilgax is after. He also makes an appearance as an NPC in Cartoon Network Universe: FusionFall.

Kevin Levin

 * Michael Reisz - Ben 10 (Season 1, 11 years old)
 * Charlie Schlatter - Ben 10 (Season 2 and 4, 11 and 43 years old)
 * Greg Cipes - Ben 10: Alien Force and Ben 10: Ultimate Alien (16 and 17 years old)
 * Nathan Keyes - Ben 10: Alien Swarm

Kevin Ethan Levin, Kevin, is a seventeen year old (eleven in Ben 10, sixteen in Ben 10: Alien Force, seventeen in Ben 10: Ultimate Alien-present) Osmosian/Human hybrid with the unique ability to absorb any type of matter or energy through his body at will in order to utilize it in various ways.

Kevin became a threat during the first show from absorbing energy, an action that warps an Osmosian's mind as a result. After accidentally absorbing some energy and demolishing his family's house, Kevin's warped mental state convinced him that his stepfather, Harvey Hackett, had convinced his mother to throw him out. Running away from home, he eventually ended up in New York City, making a home for himself in the subway tunnels. He befriends Ben in their first encounter in order to use the Omnitrix's power to take out his anger on everyone who treated him like a monster because of his abilities. However, absorbing too much of the Omnitrix energy causes Kevin to turn into a chimeric hybrid of the alien forms and swears revenge on Ben for it. Eventually, Kevin ends up at the Null Void where he manages to regain his human form and fully master his abilities under the guidance of an inmate. He eventually manages to escape and became involved with the intergalactic black market. However, his involvement during the Highbreed invasion causes him to team up with Ben and Gwen, leading him to live his dream of being a Plumber like his father, reconciles with Ben, and starts a romantic relationship with Gwen over time.

Though able to start on a new leaf, Kevin still acted out of his own interests at time and has trouble forgiving others. During Vilgax's challenge to Ben, Kevin accidentally mutated into a living colossus composed of steel, Tadenite, concrete, and wood.This space of time showed Kevin's insecurities about his relationship with Gwen. During his second mutation he gained the ability to turn his limbs into makeshift weapons. When the Omnitrix was destroyed, Kevin reverts back to normal, retaining his ability to shape shift after copying matter, as well as gaining the ability to secrete a liquid form of whatever material he has absorbed or manipulate the material when he is touching it.

Ben 10: Ultimate Alien features more about Kevin's past (from the original series to be precise). Kevin still has the ability to change his hands into different weapons even after he returned to normal in Alien Force. During the events of Ultimate Alien, Kevin is forced to absorb the Ultimatrix's energy in order to stop Aggregor, sacrificing his mental stability in the process, and became insane as a result and a monstrous combination of Ben's newer aliens. After absorbing the energies in Aggregor, Kevin goes on a revenge spree against anyone who wronged him. However, unlike when he was eleven, Kevin is more of an anti-villain rather than a true villain, and has shown that he still retains some of his heart and humanity despite going insane after absorbing the Ultimatrix's energy. This is best seen in "The Enemy of my Enemy", when he spared Gwen's life instead of killing her, saying: "The only reason you're alive is because of what you used to mean to me". In the two-part episode "Absolute Power", Kevin had absorbed the powers of Alan Albright, Manny, Helen, Pierce, and Doctor Viktor. Gwen tries to reason with him which occasionally failed, even the reasoning from Grandpa Max and Kevin's stepfather didn't go through, in a last stand in Los Soledad, Ben as Ultimate Echo Echo, finally managed to bring him down;showing uncharacteristic coldness.However,Cooper was able to cure Kevin, resulting in Gwen and Kevin sharing a passionate kiss.

Kevin makes appearances in all five games based on the series. He appears as a boss in "Ben 10: Protector of Earth", and a playable character in "Ben 10 Alien Force: The Game". Kevin also makes an appearance in Cartoon Network Universe: FusionFall as an NPC and a boss (Having been brainwashed by the main antagonist).

Julie Yamamoto

 * Vyvan Pham – Ben 10: Alien Force and Ben 10: Ultimate Alien

Julie Yamamoto is a sixteen-year old Asian-American student (fifteen in Alien Force, sixteen in Ultimate Alien), who is Ben's girlfriend; her first appearance was in the first episode of Ben 10 Alien Force, where Julie congratulates Ben on his soccer win, sparking Ben's feelings. Julie later plays a bigger role when Ben manages to ask her out on a date (with help from Gwen). Their romantic evening at the pier is interrupted by "Ship", who kidnaps Julie to get Ben to help him. But, when Ben reveals his secret to Julie during the rescue attempt by accident, she finds the Omnitrix "cool", which surprises him. Afterwards, she became Ship's guardian, treating him as if he was a normal dog. Julie is quite accepting of Ben's Omnitrix-fueled exploits. Besides being good at tennis, she is also good in school. In some cases, she can use her connection with Ship to help Ben from within a suit of battle armor made of Ship himself. In Ben 10: Ultimate Alien, Julie showed more interest in the relationship with Ben. In the first episode, she gave him a kiss on the cheek, to give him courage to deal with society. In "Duped", she was displeased with him after he embarrassed her in her tennis game and trying to be in three places at once. In "Hero Time", she was no longer angry at Ben, but she was jealous of movie star Jennifer Nocturne because she kissed him after he saved her. Later, Julie ends up kidnapped alongside Jennifer Nocturne by Captain Nemesis, then, after Ben saves her life, he calls her "his girl" and she forgave him for all his flaws, instead of Jennifer (she was saved by Gwen and Kevin at the moment). It is said that they are back together again. However, in "Eye of the Beholder", Kevin said to Ben that Julie had dumped him in "Duped" because he was being a jerk, but after Ben apologizes to Julie for all his mistakes, he promises to make it up to Julie by being a better boyfriend and as Julie accepts, she promises to do the same. In "Revenge of the Swarm", she was kidnapped by Elena Validus because of she jealous when she found about her. Ben finds Julie and frees her. Elena used the Nanochips to stop him, but, instead, it was killing him. Julie convinces Elena to stop. In this episode, she seems to have no jealousy of Elena, despite her trying to keep Julie away from Ben until she convinces Elena to save his life, different from "Hero Time", but that she still cares for Ben. It's possible she had known about Elena just recently when she was kidnapped, until Ben saved her.

Azmuth

 * Robert David Hall – Ben 10: Secret of the Omnitrix
 * Jeff Bennett – Ben 10: Alien Force and Ben 10: Ultimate Alien

Azmuth is a thousand year old Galvan (same species as Grey Matter), as well the genius and pessimistic creator of the "Omnitrix", the "Ultimatrix" and the "Unitrix". He originally created the Omnitrix to help people of the galaxy to better understand each other, and also as an alien version of Noah's Ark to preserve the DNA of over one million species, but was disgusted when some people, particularly Vilgax, considered it to be a weapon. He built numerous security systems into the device, which is why Ben had some problems using the Omnitrix, including a self destruct function that would destroy the entire universe. He is an extremely intelligent being, even as far as Galvan go, Azmuth's scientific prowess and achievements have made him a respected scientist even to the other Galvan, Paradox has even called him the smartest being in the universe.

When the Omnitrix's self destruction mode activates, Ben, Gwen, and Tetrax look for him in the hopes he will deactivate it. When they finally find him, he refuses at first, saying that the universe doesn't deserve to be saved, but eventually accepts after Ben gave him back some faith in life, and unlocks the alien form Way Big. Azmuth tells Ben that he has a lot to learn about the Omnitrix, and allows it to remain with Ben, both because of Ben's using it for his intended purpose and because it is a magnet for trouble.

In Ben 10: Alien Force, Azmuth's former assistant Albedo creates a copy of the Omnitrix. After the copy nearly destroyed a galaxy, Azmuth shows up and punish Albedo by breaking his false Omnitrix, leaving him de-powered and trapped in Ben's human form, before sending him to prison. He then stated that Ben is the only one who used the Omnitrix for good, and decides to let him find his own way to use it rather than advise him saying that he has far more difficult challenges ahead and that he isn't the only one who believes Ben is the only one who thinks so.

Later, Azmuth and Paradox warn Ben that the Highbreed are conquering planets and their fleet is heading towards Earth. His planet was already conquered by the High-Breed and its destruction would be the beginning of the end. Although he doesn't want Ben to fight, he realizes that there's no stopping him and activates the Master Control for the sake of the battle. When the Master Control was reset by the DNA wave Ben used to stop the High-Breed, Azmuth left to help rebuild Galvan without reactivating it, telling Ben to "have fun figuring it out".

In contrast to his first appearance in Ben 10: Secret of the Omnitrix where he is shown to be quite sarcastic and egotistical, in Ben 10 Alien Force, Azmuth is depicted as being less pessimistic and more serious. He shows a no-nonsense attitude towards the High-Breed's plan to eradicate Earth and he warmly tells Ben that there are more difficult battles to be fought in the future. This change in personality might be due to his encounter with Ben teaching him to be more optimistic.

When Ben and Kevin try to hack the Omnitrix, Azmuth contacts him telling him not to tamper with it, stating that he will learn the Master Control when the time is right. When an accident unleashes Chromastone, Goop, Spidermonkey, and Way Big from the Omnitrix, Azmuth instructs Ben to reabsorb the alien forms into the Omnitrix. Dissatisfied at what happened, Azmuth also tells Ben that he won't help him again.

When Ben, Gwen, and Kevin ended up on Primus when the Omnitrix takes them to its "place", they find Azmuth using the Omnitrix to fight Vilgax. But despite being its creator, Azmuth isn't as skilled in using it in combat and ends up defeated. Azmuth tells Ben to get off the planet. He reveals that Primus was an artificial planet of his creation alongside the incectoid Voloticus Biopsis that collected the DNA samples. Azmuth arrived when it was threatened by Vilgax. After Vilgax was defeated and Ben retrieves the Omnitrix, Azmuth concludes that he will have to move Primus and hide it somewhere else. Though he still hasn't forgiven Ben for damaging the Omnitrix, he allows him to keep it nonetheless.

After Albedo steals the "Ultimatrix", Ben is defeated and the Omnitrix is taken by Vilgax. Azmuth only found Ben in the woods in "The Final Battle: Part 2" because he started looking for him when the Ultimatrix core was stolen, Ben is briefly visited by Azmuth and told about the situation, and Azmuth also stated that the Omnitrix was originally meant for Grandpa Max. To stop Vilgax from using it to take over the world, Ben uses the Omnitrix's self-destruct code to destroy it, then threatens Albedo with the code to give up the Ultimatrix. At present, Azmuth has allowed Ben to keep the Ultimatrix.

In "Map of Infinity," Azmuth returns and warns Ben that Aggregor is going after the four pieces of the Map of Infinity. In "The Forge of Creation", Azmuth was displeased that Ben, Gwen, and Kevin failed to stop Aggregor from claiming the Map of Infinity. Following Ben's failed attempt to get the Bellicus and Serena parts of Alien X to help, Paradox arrived and ended up in an argument with Azmuth until they agreed to explain what the Forge of Creation is.

Azmuth appears in "Ben 10 Alien Force: Vilgax Attacks" and "Ben 10 Ultimate Alien: Cosmic Destruction", and also appears in "Cartoon Network Universe: FusionFall" as an NPC.

Plumber's Helpers
This group is made of sons of Plumbers, most are hybrids, part of alien, part human, with super powers, most with powers of some aliens of the Omnitrix and the Ultimatrix. They are allies of Ben's team and are currently being training by Max Tennyson after they worked in the war of the Highbreed; in the end, they become pupils under Max. Much to Max's annoyance, they insist on calling the new team "Max Force".

In the season 3 premiere, Max and the other Helpers try to take down Vilgax in the park but they were stomped out of the way.

To test the Plumber's helpers, Max and Ben came up with a plan to trick Helen, Pierce, Manny, and Alan into believing that Ben had gone rogue, and attacked his Grandpa aboard a satellite. Each member of the Plumber's Helpers had initially decided to go on their own to stop Ben, but they were only able to defeat him when they worked together. Unfortunately, their battle with Ben had caused the satellite to fall towards Earth. To prevent the deaths of thousands, Helen, Pierce, Manny, and Alan decide unanimously to sacrifice their lives to cause the satellite to self-destruct. Max appeared in time to stop the self-destruct, stop the satellite from colliding with Earth, and tells the Plumber's Helpers that they had passed the test, and were on their way to Plumber's Academy. Cooper was absent in "Above and Beyond".

The helpers returned in Ben 10: Ultimate Alien; in "Absolute Power" Pt. 1, Alan mentioned all of them, except Cooper was defeated by Kevin who drained him of his powers, along with Dr. Viktor. What Kevin did to them after he stole her powers is unknown, but they may have gotten her powers back after Kevin was changed back to normal.

Cooper Daniels

 * Cathy Cavadini – Ben 10
 * Corey Padnos – Ben 10: Alien Force
 * Chris Pratt – Ben 10: Ultimate Alien and Ben 10 Ultimate Alien: Cosmic Destruction

Cooper Daniels is the son of a Plumber. In his first appearance in the original series, he was given a ride home by Ben, Gwen and Max. Cooper is a genius with technology, in part thanks to his unique technopathic powers, which allow him able to mentally merge with and control electronic devices, both terrestrial and alien, either activating it or creating new machines and to communicate with any sort of machinery, either activating it or creating new machines, turned the color of his eyes into a bluish color with a robotic-like print on them to show his connection to technology; this power became crucial in defending the Mt. Rushmore base from the Negative 10. He was the first Plumber's descendant with special abilities introduced in the story, though it is not shown or explained if his powers come from being descended from an alien, or if they're just a special ability he has come to exhibit.

Cooper reappears as a teenager in Ben 10: Alien Force, where he's become considerably obese due to spending too much time in his lab on the computer. The DNAliens capture him in and force him to use his technopathic powers to build a mysterious arch and a holographic projector to hide it the place. He's released by Ben, Gwen and Kevin, and destroys the projector. Cooper has since developed a crush on Gwen, which she can't help but be annoyed about, although Kevin usually shows jealousy when other boys crush on Gwen, he's surprisingly good-humored towards Cooper's teenager feelings. In "War of The Worlds", after studying the Omnitrix's ability to restore the DNAliens to humans, he dismantles his suit to create ray guns that copy the effect.

In Ben 10 Ultimate Alien, Cooper has shown to have had a growth spurt and is now considerably taller and more muscular, his voice deeper, and his overall appearance like that of a surfer, while unknown to what degree, he was shown after his growth spurt strong enough to plow through a wall. In the episode "Absolute Power", he helps in devising a device that would cure Kevin of his amalgamated form. He reappears in "Prisoner #775 is missing," where it's revealed he has become a Plumber.

Cooper appears in "Ben 10 Alien Force: Vilgax Attacks", and as a boss in "Ben 10 Ultimate Alien: Cosmic Destruction". He ends up under the control of Psyphon's R.E.D.s and fought Ben in Japan. Ben defeats him and turn him back to normal, and Gwen send him home to search after other Plumber Helpers. On the DS Version, Ben encounters him in Venezuela and reverts back to normal.

Alan Albright

 * Zeno Robinson - Ben 10: Alien Force and Ben 10: Ultimate Alien

Alan Albright is a teenager half human, half Pyronite (based on Heatblast's species).

He is a son of a Pyronite Plumber from whom he inherited the Plumber's Badge that he wears on his chest, which gives him a strong resemblance of Heatblast. Alan discovered his powers not for to long, that is why he can not control his powers very well, including to fly.

Alan returned in Ben 10: Ultimate Alien, in "Absolute Power" Pt. 1, Alan was defeated by Kevin who drained him of his powers. In the same episode, he is referred to as Heatblast by both Max and the ending credits. At some point, Alan must have taken the name as his alias. Whether or not Ben gave him permission is not clear.

Helen Wheels

 * Juliet Landau - Ben 10: Alien Force

Helen Wheels is half human half Kineceleran (the same species of XLR8) whose a Plumber.

She was originally part of a small team of "Plumber's helpers", young plumbers’ apprentices, with her adoptive brother Pierce and their friend Manny. Helen is smart, brave, kind, nifty and level-headed, though at times she usually tries to act rational and wise, making her mostly a mirror image of Gwen, usually prefers a more careful and less aggressive approach, causing occasional argument between she and Manny, sharing a specific love-hate relationship with him, which she might have a crush on him. Helen has quite skilled with computers and technology and has the same skills as XLR8, as well as a visor, though it only covers her eyes.

Helen and Manny used to hunt all sorts of aliens they confused for criminals whom they would throw into a Null Void projector, which they've mistaken for a disintegration weapon. Manny convinced Helen that Ben, Gwen, and Kevin are DNAliens, but the confusion is eventually cleared up after Ben proves that the Null Void projector is not a disintegration weapon. To rescue those they may have falsely imprisoned, because part of those they captured probably were Plumbers kids, Helen and Manny travel into the Null Void. Later, Helen telepathically contacts Gwen for help against Dr. Animo, which Ben provides.

Manny Armstrong

 * Khary Payton – Ben 10: Alien Force

Manny Armstrong is a Plumber's son whose the same species of Fourarms, though he seems to be slightly smaller and weaker, presumably because he's a hybrid. Like Kevin, Manny is hot-headed, aggressive, rebel, and sometimes cocky often willing to fight even when it may be not necessary, exhibits an anti-hero personality and is stubbornly dedicated to their mission, immediately assuming that Ben, Gwen, and Kevin are DNAliens, he lacks his mirror's laid back attitude, often permanently angry and insulting to even his own allies, earning him the dislike of Kevin and Ben and forcing Helen to act as peacekeeper. Manny is finally convinced to listen after being brought down by Ben, after learning the error of their ways, Helen and Manny travel into the Null Void to search for those they've wrongly imprisoned.

Manny shares a love-hate relationship with Helen: while his hot-headed attitude, when confronted to Helen's wiser personality, cause them to often fight, he is shown to truly care about her, being once willing to attack Ben after he hurt her in "Above and Beyond". Several hints suggest Manny might have a crush on Helen in nearly all of their appearances.

Later in the Null Void, Manny is one of the resistance fighters battling Dr. Animo, a past battle cost him a hand, which has been replaced with a crude clamp. Much to Max's annoyance, he insists on calling the new team "Max Force", in addition to his Tetramand powers, Manny also carries 2 sets of handguns that fire plasma beams.

Pierce

 * Adam Wylie – Ben 10: Alien Force

Pierce, like Alan, Manny, and Helen is half human, half alien species, a son of a plumber, and the adoptive brother of Helen. His species remains unknown.

He has the ability to sprout quills from anywhere on his body, similar the Porcupine in "Ready to Rumble", and combines it with martial art skills. He first appears in a recorded journal having reportedly died in the "disintegration weapon" during a mission while working with Helen and Manny. It is later revealed that he was actually sent to the Null Void, presumably through the projector they had been using to dispose of DNAliens (and a number of other aliens). Like Manny is a mirror image of Kevin and Helen is the same to Gwen, Pierce is a mirror image of Ben on the team

Ben is forced to spar with Pierce in order to see the Wrench (who turned out to be Grandpa Max) and loses, though Pierce later finds out that Ben let him win in order to be allowed to see the Wrench.

Ship

 * Vyvan Pham - Ben 10: Alien Force and Ben 10: Ultimate Alien

Ship is a symbiotic of canine behavior produced by a Galvanic Mechomorph named Baz-El.

He possesses the same powers as Upgrade, in particular fusing with machines to control and upgrade them. He can also alter his form to mimic any device he has come into contact with; even objects with substantially more mass, like the Forever Knights's space ship, after this, Ship became the main transportation of Ben's Team until Ben 10 Ultimate Alien when Kevin got The Rust Bucket III. Ship's vocabulary is limited to the word "ship", the message its creator had sent it to deliver, the word is adopted as the creature's name, but it turns out that Julie seems to understand what ship says to her, in the other hand, in "The Eye of the Beholder" Ship speaks his first word other than "ship" which is "Julie".

Ship became Julie's pet since "Pier Pressure", after Baz-El gave to her, Julie really cares about him, and so as Ship, having developed an attachment to Julie.

In "Ben 10 Alien Force: Vilgax Attacks", Ship was used as the transportation to the other planets. He also makes an appearance as an NPC in "Cartoon Network Universe: FusionFall"; both in his Galvanic Mechomorph and Ship forms.

Paradox

 * David McCallum - Ben 10: Alien Force and Ben 10: Ultimate Alien

Professor Paradox is a scientist from 1952 who was working on a time-travelling experiment with his assistant Hugo at the military base Los Soledad during the Cold War. However, during a test of his time tunnel, Hugo damaged the controls, destabilizing it and sucking Paradox into the event horizon. His body didn't age, and he didn't need to sleep or eat, just exist. Being trapped in the time stream, alone, for untold millennia drove him insane, but that eventually became boring so he regained his sanity. He learned everything there is to learn about time, allowing him to finally escape.

As a result of his time spent in the event horizon of a wormhole, Paradox can control time through will alone. He can teleport to any location, both in time and space, and slow down or speed up time as he pleases without reason, and being unaffected by time, he is biologically immortal. He is also able to create a breathable atmosphere on the moon for Ben, Gwen, and Kevin. His actual name is unknown as he himself forgot it over the millennia, the file with the information censored every aspect of the professor's personal life, name included; he is given the name "Professor Paradox" by Gwen because his experiment was listed as the Paradox Project. He seems to get confused about events occurring as a result of his traveling through time, mixing up events that haven't happened yet (from Ben, Gwen, and Kevin's perspective) with those that have.

At some point in his career, Paradox separated the pieces of the Map of Infinity (which could lead a person to the Forge of Creation), and hid them across the universe, disguising them as objects which would be difficult to obtain, in order to prevent the map from falling into the wrong hands.

In "Paradox", Ben, Gwen and Kevin had their first encounter with Paradox (Which, due to his time-travelling nature, was not his first encounter with them). They helped him battle a time monster, later revealed to be Paradox's assistant, Hugo, who had been transformed by the same accident. The present-day Hugo agreed to travel with Paradox, but has not been seen since. The enhanced version of Ben 10: Race Against Time states that Paradox also stopped Eon prior to the events of the movie. In "War of the Worlds", Paradox retrieved Azmuth from the Highbreed-ravaged Galvan, and assisted in battling the Highbreed. In "Time Heals", Paradox warned Gwen against travelling back in time to prevent the accident that turned Kevin into a monster. When Gwen refused to heed his warning, creating a nightmarish alternate timeline, Paradox pointed her towards solving it. When the timeline had been put right, Paradox paid the group a visit, making sure everything was alright.

Paradox been described as a calm, free-going man; he talks much like a stereotypical scientist, with dialogue requiring higher knowledge to understand completely. In his first appearance, Ben tried to capture Paradox (not knowing whether he was an enemy or not) but he always "teleports" to a place a few meters away. Ben asks how does he do that and the calm Paradox just said: "It's called walking". He really likes gumballs possibly because they virtually don't age. He also has a habit of getting events that haven't happened yet (from the perspective of the viewer and those he's talking to) and those that have (from his perspective) mixed up, due to his travels through time. His calm personality also makes it difficult to tell when he's joking or not, such as telling Kevin that if his replacement car (factory new from the past) comes in contact with anything else from the same year it'll explode like antimatter.

In the Ben 10: Ultimate Alien episode "Ultimate Aggregor", Paradox informed the team that Aggregor was using his old time travel equipment to achieve his goals. He also gave Kevin advice concerning the future, telling him that things would get worse before they got better, and to try to remember who his friends were. He also warned Ben "not to lean against the coronal reduction barrier", but doubted that he would listen. In "The Forge of Creation", Paradox appears to help the team to go to the Forge of Creation, which is outside the universe, but is unable to stay with them as the Celestialsapiens there have "placed a restraining order on their home". He also appears in "Ben 10,000 returns" to bring the Ben 10.000.

It is possible that Paradox is inspired by the Doctor of the British television show Doctor Who, as they have similar traits, for instance their English accents and dislike of guns. Furthermore, Paradox at one point prevents Ben 10,000 from revealing the future to young Ben by saying "Spoilers", a line that The Doctor uses in similar situations.

In "Ben 10 Alien Force: Vilgax Attacks", Paradox appears before Ben, Gwen, and Kevin during Vilgax's alien invasion stating that now would not be a good time to use Alien X. After Ben's visit from Azmuth, Paradox arrives and rewinds time so that Ben could head to the different planets and destroy the energy cores before Vilgax can use them for his invasion on Earth. Paradox even gets Ben, Gwen, and Kevin off of Anur Phaetos. When Vilgax and Psyphon were about to fire the Null Void Cannon on Ben, Paradox arrives telling Ben that now is the time to use Alien X.

Paradox also appears as an NPC in "Cartoon Network Universe: FusionFall" where he tells the players that they will have an encounter with Vilgax.

Jimmy Jones
James "Jimmy" Jones is a 10 year old kid who is a major fan of Ben Tennyson and his alien heroes. He runs a website with pictures of aliens around the world, including every alien Ben has ever turned into, even when Ben was ten. He watches Ben by alerting him about any alien activity he finds via the internet. In "Andreas' Fault", Jimmy is revealed to have a secret informant in the Forever Knights in the form of Foreverduke838 (whom Jimmy met online), Ben realizes that Jimmy is very useful for letting him do what he wants, even giving Ben "relationship advice" and helping on fights, as seen in "The Big Story", when Jimmy helped to save them, retrieve the Ultimatrix for Ben, and defeat the plant alien.
 * Scott Menville - Ben 10: Ultimate Alien

He wears a hoodie similar in design to Ben's jacket and has Ben's old pants from the original series. Jimmy sent out a video that finally showed the world that Ben has the ability to turn into aliens, as he thought Ben would like the attention and money. He now helps Ben in some episodes but gets cut short by his mother.

Aggregor's Prisoners
These aliens are from the Andromeda Galaxy, and they were kidnapped from their planets by an Osmosian called Aggregor, he wanted to absorb the full powers and abilities of the five aliens he captured using a machine he had built back on his home planet and make himself invincible so he can obtain the "Ultimate Prize".

All them escaped from Aggregor's ship using a shuttle, and crashed a land on Earth on the coast of Florida, afterwards, Galapagus, P'andor, Andreas, and Ra'ad each split up to find a way off the planet while Bivalvan stays with the shuttle and attempts to repair it. But all the aliens were recaptured.

In "Ultimate Aggregor", after regain all them, Aggregor releases them, but takes control of their minds and has them attack Ben and his friends, to bring more time for his plan be successful. When Aggregor used the machine to drain the aliens' powers they faded away.

In "Absolute Power" Pt. 2, all the aliens that Aggregor killed and drained their powers were brought back to life after Ben and the others stopped Kevin, releasing their powers.

Bivalvan

 * Dee Bradley Baker - Ben 10: Ultimate Alien

Bivalvan (a play on bivalve, a term for clams and oysters) is a crustacean-like creature, he can breathe under water for a short period of time, has an armored exoskeleton, and can shoot pressurized water from his hands.

Every night he would rise out of the ocean and raid NASA, steal equipment from their secret rocket project, and use them to repair the ship. Unfortunately if he had launched the ship, the nuclear bomb he used to ignite it would have destroyed most of Florida. Ben, Gwen, and Kevin were able to stop Bivalvan from launching his ship, scanned his DNA, and promised that they would send Plumbers to get him and send him back to his home planet. Instead, Aggregor arrived before the Plumbers and recaptured Bivalvan.

Galapagus

 * John DiMaggio - Ben 10: Ultimate Alien

Galapagus (a play on the Galápagos Islands which are home to the Galápagos tortoise) is from a peaceful planet called Aldabra. A turtle-like creature, he has the ability to fly and create wind waves. Like the other members of his species, he's gentle, kind, and easily scared.

One day, Aggregor attacked his home planet, captured him, and imprisoned him with the other four aliens he had captured. When the five attempt to escape Aggregor's ship, Galapagus suggests using his communicator to send out a distress message. Even though he and the other aliens are put back in the cell, Galapagus's message is heard by Magister Prior Ghilhil, who boards Aggregor's ship and finds the five aliens, only to be attacked by Aggregor. Bivalvan, P'andor, Andreas, and Ra'ad manage to escape again, but Galapagus seemingly betrays them to Aggregor in exchange for his own freedom. When Aggregor admits he wasn't going to free Galapagus, he admits he didn't intend to betray the others either and incapacitates Aggregor. He then leads the escape to a shuttle, which Aggregor shoots down and causes it to crash on Earth. Afterwards, Galapagus, P'andor, Andreas, and Ra'ad each split up to find a way off the planet while Bivalvan stays with the shuttle and attempts to repair it.

Seeking help, Galapagus attacked Bellwood's downtown to get the attention of Ben. While battling, Gwen notices that Galapagus hadn't actually harmed anyone, and convinces Kevin to use the translator in his Plumber's badge to translate his words into English. After hearing Galapagus's story of how he escaped Aggregor, Ben scanned samples of his DNA for the Ultimatrix, and has him taken back to his home planet in a Plumber spaceship. However, Galapagus finds out the spaceship's pilot is Aggregor in Magister Prior Gilhil's Plumber suit.

Aggregor's needs for Galapagus’s powers were made apparent in "Where the Magic Happens", as his species is immune to mana.

P'andor

 * Dee Bradley Baker - Ben 10: Ultimate Alien

P'andor (a play on Pandora's box) is a radioactive energy being trapped inside an armored suit that limits his powers, though he's still able to make the armor's gauntlets hot enough to burn or melt anything he touches. Outside his suit, he can fly, shoot, and drain energy for food. He's the most aggressive and hot-headed of the five aliens. P'andor is being more aggressive than others, and seemed to have a rivalry going with Bivalvan and had a tendency to berate Andreas for not thinking.

Desperate to return to full strength, he ends up establishing a reward to whoever can break open the suit. When the hired help consisting of Buzz, Hammer, and Surgeon are unable to use the Taedenite to break it open, P'andor sends them to capture Kevin. Upon his hired help capturing Kevin, P'andor tricks Kevin into releasing him from his containment suit (the only thing limiting his powers). Revealed as a living energy being, P'andor attempts to drain the radiation out of a nuclear power plant, but also his presence in the Earth without his suit was dangerous, because he is radioactive. Kevin and Ultimate Cannonbolt are able to trap him back in his suit and turn him over to the Plumbers who deport him back to his home planet. Unfortunately, their ship is intercepted by Aggregor who blasts the Plumbers out into space and recaptures P'andor. In "To Hot to Handle", P'andor was the only antagonist between the Andromeda Galaxy aliens.

Andreas

 * John DiMaggio – Ben 10: Ultimate Alien

Andreas (His name and the name of the episode "Andreas' Fault" are a play on the San Andreas Fault) is a large, bulky, yellow, armored alien with jackhammers and drills in his arms, Andreas has the power to drill through the earth, as well as the ability to cause massive tremors. He is reckless, as well as oblivious, proven when he repeatedly attempted to wreck a spaceship while still inside it. His intelligence is quite low and doesn't even know what an asteroid is. However, being dimwitted, he often uses these powers at the inconvenience of allies and enemies alike. His personality and actions are very similar to Rath. On the other hand, Andreas is a little more gullible than hardheaded as he tends to make attachments to pretty much anyone whom he thinks is nice or is the strongest (this was proven when he blindly followed P'andor who had over-powered Bivalvan and took charge). Andreas has shown him to be a gentle giant, getting easily scared and thinks most people are his friends.

Some time after he separated from the others, he met up with Argit who became Andreas's "friend". Argit then took command of the Forever Knights by threatening to use Andreas to destroy their castles. His plan backfires when the Forever Knights rebel and capture Andreas, Argit, Ben and his friends. Andreas is to be executed but Ben and his friends save him and considers them friends. When the Forever Knights set a weapon to self-destruct, Andreas decides to save his friends by absorbing the blast on Argit's suggestion. Andreas saved them and was assumed dead by everyone. Miraculously, Andreas survived but was greatly injured, which made it easy for Agreggor to arrive and capture him once more.

While he was on Aggregor's ship, he was much braver, but on Earth, Andreas's personality is like that of an innocent child. He scares easily but takes comfort in his friends, whether they are bad or good.

Ra'ad

 * Dee Bradley Baker – Ben 10: Ultimate Alien

Ra'ad (a play on Ra'ad the popular Arabic male given name for thunder) is an Amperi, he has the ability to produce and control electricity, making him able to levitate by magnetism, shoot lightning, travel through electrical systems and read minds. Preferring to be quiet and observant questioning Galapagus's trust briefly and agreeing that Bivalvan's plan was the best. He also appeared somewhat controlling, having a short argument with P'andor over power but quickly changed his mind and went along with Bivalvan.

After learning that Aggregor had captured the others, Ra'ad attacked Ben, and blaming him, thinking he had given the others aliens to Aggregor. Ben defeated and captured him, but Ra'ad duped them to letting him go, under the pretense of friendship. Ra'ad then entered the Ultimatrix forcing Ben to change into his form, and slowly taking control of his mind, but while he was undercover, he kept the Ultimatrix off-line, so Aggregor couldn't tracked him. Kevin was able to force the Ultimatrix to reboot, knocking Ra'ad out of it. Sensing Aggregor's approach, he fled, leaving Ben and company to fight him. However, after being scolded about his cowardice by Kevin, he returned, saving Ben from Aggregor's attack. But in doing so, he ended up getting recaptured by Aggregor.

Cash and JT
Cash
 * Dee Bradley Baker – Ben 10
 * Tyler Patrick Jones – Ben 10: Race Against Time
 * Matt Levin – Ben 10: Alien Force and Ben 10: Ultimate Alien

JT
 * Adam Wylie – Ben 10
 * Tyler Foden – Ben 10: Race Against Time
 * Yuri Lowenthal – Ben 10: Alien Force (In "Ben 10 Returns" Pt. 1)
 * Scott Menville – Ben 10: Alien Force (In "The Gauntlet") and Ben 10: Ultimate Alien

Cash and JT are recurring bullies from Ben's school. Cash Murray is taller and has darker skin, JT is the shorter and wears glasses. They are modeled after series producers Sam Register and Tramm Wigzell.

In Ben 10: Alien Force, Cash and JT found an alien tech gauntlet in Kevin's car that shot lasers. While taking turns using the Gauntlet, Cash became addicted to the weapon's power, and attacked JT when he tried to take it from him. After beating Kevin and declaring himself the "coolest guy in the neighborhood" Cash challenged Ben to a one-on-one battle. With JT's support, Cash realized that the armor was controlling him, and broke free of its power. Since then Cash and JT have been more friendly towards Ben, and are among the first to show their support when Ben's identity as a "hero" is exposed to the public.

In the Ben 10: Ultimate Alien pilot episode "Fame" Cash and JT applaud Ben at school after his secret has been exposed. In "Reflected Glory", JT and Cash try to take credit for Ben's plans, and use Oliver Thompson to help them to make a TV show in which they claim to be the brains behind Ben 10, like what they did in "The Unnaturals". Psyphon, on a mission to gain Power Decouplers for the Forever Knights, goes after JT and Cash since they claim to be the brains behind Ben 10 and are therefore responsible for the defeat of Vilgax, Psyphon's master. In order to save themselves JT and Cash are forced to admit they were lying about everything causing Psyphon to turn his attention to Ben only. At the end of the episode Ben was in danger of being killed by Psyphon, so JT and Cash use the "Power Decouplers" to shoot Psyphon, taking him out and saving Ben's life. However, shooting the Power Decouplers breaks Oliver's camera, destroying everything they recorded, including the scene where they save Ben. With no footage and its stars discredited, Oliver subsequently cancels the show and leaves Cash and JT behind.

Tetrax Shard

 * Dave Fennoy – Ben 10 and Ben 10: Alien Force

Tetrax Shard is a Petrosapien (same species as Diamondhead) mercenary. Coincidentally or otherwise, he also happens to be one of the types of aliens in Ben's Omnitrix. He has nearly impenetrable gray and black armor, a black helmet with a small, green triangle (presumably for sight) on it, and carries a large rifle. His Petrosapien physiology can manifest through the armor, allowing him to use his powers without removing it.

Tetrax was originally a selfish bounty hunter until he accepted the job to steal his people's sacred crystal and deliver it to Vilgax. After the galactic warlord used it to destroy his home world Petropia, Tetrax felt guilty, and became concerned about who he worked for, and started trying to be sure Vilgax would not get other weapons of mass destruction (such as the Omnitrix).

Under the alias of "Hoverboard", Tetrax was hired by Vilgax with Kraab and Sixsix to take the Omnitrix from Ben. However, it's soon revealed he's actually working for another unnamed force that wants him to assure Vilgax doesn't get the Omnitrix. When he initially meets Ben, he criticizes his lack of strategy, and tries to take him with him in order to deliver the Omnitrix to his true hirer. When Kraab and Sixsix then choose to team up against Tetrax, Ben is able to use strategy to defeat the two of them, causing the Petrosapien to agree to let him stay on Earth, since the Omnitrix is in good hands.

Tetrax comes back in Ben 10: Secret of the Omnitrix, where he helps Ben and Gwen travel in space to find Azmuth so he can disable the Omnitrix's self-destruct mode.

In Ben 10: Alien Force Tetrax discovers the Petrosapien Crystal was actually a backup for his planet and his people, containing all their memory and DNA. Learning this, he stole it from Vilgax and freed Sugilite (Chromastone's genetic donor) from the Omnitrix, so he could use the crystal to bring back Petropia. Despite Vilgax almost killing Sugilite, the planet is brought back thanks to Ben.

Tetrax makes an appearance in "Cartoon Network Universe: FusionFall" as an NPC.

The Galactic Enforcers
The Galactic Enforcers are a group of super heroes Ben first encountered in their titular episode.

In the episode "Ben 10,000", set 20 years into the future, Ben's otherwise perfect patrol route left them out of a job and they were forced to clean up after Ben, bringing the criminals he captured to the authorities. Near the end of the episode, Ben lets them deal with the Circus Freaks while he attends Grandpa Max's birthday party.

They appear briefly in the beginning of the third season episode "The Vengeance of Vilgax Part 1". Synaptak and Tini were quickly defeated by Vilgax but he only absorbed Ultimos' power with help of Psyphon. Afterwards, it's unknown what became of them.

Ultimos

 * Tom Kane – Ben 10
 * Jeff Bennett – Ben 10: Alien Force

Ultimos is from Specimen Prime and leader of the trio. He has Superman-like powers complete with flight, super strength, durability, and heat vision. Upon arriving on Earth, with Ben's help, he and his team managed to quickly capture Sixsix and Vulkanus but the two escaped due to an argument between Ben and Ultimos on how to bring the villains in (Ultimos's by-the-book peaceful tactic compared to Ben's beat down tactic) but he still made Ben an honorary associate. It is shown that he has a dangerous reaction to chocolate, effectively his Kryptonite. Synaptak identified it as a common poison across the galaxy but Ultimos was still quickly able to recover. Despite his by-the-book personality, he's shown to like Ben's approach to fighting, stating that it makes him feel free.

Synaptak

 * Greg Ellis – Ben 10 and Ben 10: Alien Force

Synaptak is a floating telekinetic brain in a jar with a computerized face and tentacles. Effectively the brain of the group, he's shown to have an enormous crush on fellow member Tini, showing great jealousy over Tini's crush on Ben, which Ben easily managed to take advantage of, saving both his new teammates and his family from a rock slide. At the end of the episode, the two hook up.

Tini

 * Vanessa Marshall – Ben 10
 * Juliet Landau – Ben 10: Alien Force

Tini is a Tetramand (Same species as Fourarms) and easily the strongest of the three, complete with all of Fourarms's powers but with better control over them. Upon arriving on Earth, she immediately met Ben as Fourarms and developed a crush on him and throughout the episode, tried to encourage him to turn back into Fourarms much to Ben's dismay. She was not aware of Synaptak's crush on her until Ben manipulated him into using his telekinetic powers to hold back a land slide, and at the end of the episode the two (Synaptak and Tini) hooked up.

Myaxx

 * Vanessa Marshall – Ben 10: Secret of the Omnitrix
 * Vyvan Pham – Ben 10: Alien Force

Myaxx is a female Chimera Sui Genris (Same species as Vilgax) who was Azmuth's assistant. She helped him in the creation of the Omnitrix, collecting several DNA samples, including the ones for Wildvine and Ghostfreak. However, since Azmuth didn't give her the credit she deserved, she left a genetic signature in the Omnitrix overwriting his, and walked away. Ironically, despite being a good fighter as well as the same species as one of the most dangerous Warlords in the Universe, she's quite a coward who doesn't like fighting and would rather try to walk away or escape if she has the chance.

In "Ben 10: Secret of the Omnitrix", Ben, Gwen and Tetrax finds her in the Prison Satellite Incarceron. Ben confuses her with Vilgax and attacks. After the confusion is cleared, Myaxx tells the group that she's the creator of the Omnitrix so they can get her out of prison, but is forced to tell them the truth once they escaped. She still agrees to show them where Azmuth is, as well as putting a device on the Omnitrix to reflect the Omnitrix's energy blasts back inside it (the energy blast only happen when the Omnitrix is in self destruct mode). When Vilgax comes to Xenon (Where Azmuth is), Myaxx helps Tetrax and Ben despite her cowardice, to fight Vilgax's minions. After Ben defeats Vilgax, Azmuth offers for her to be his assistant again. Though he admits he won't be able to treat her better than before, she agrees, preferring to be his assistant rather than go back to Incarceron.

When Myaxx appears Ben 10: Alien Force, her look is completely changed, giving her a more feminine appearance, red armor and pink eyes.

Carl and Sandra Tennyson
Carl Tennyson
 * Dee Bradley Baker – Ben 10
 * Don McManus – Ben 10: Race Against Time, Ben 10: Alien Force and Ben 10: Ultimate Alien

Sandra Tennyson
 * Tara Strong – Ben 10
 * Beth Littleford – Ben 10: Race Against Time and Ben 10: Alien Force (In "Grounded") and Ben 10: Ultimate Alien
 * Vyvan Pham – Ben 10: Alien Force (In "Ben 10 Returns" Pt. 1)

Carl and Sandra are Ben's parents and Gwen's uncle and aunt; Carl is Max and Verdona's son. In the live action film Ben 10: Race Against Time, Carl is depicted as a new-age style parent who wants Ben to have his "freedom," insisting on being called Carl, not dad, and letting Ben run off on mysterious adventures without asking questions. He seems to be even more laid back than his wife, and is seen at least twice telling her to let Ben have his fun. Sandra reveals that Ben is lactose intolerant. They appear in the Ben 10: Alien Force episode "Grounded", when they grounded Ben after finding out that he has been using the Omnitrix without permission or informing him and his wife. Later, they help Ben defeat a Highbreed and allow him to keep his Omnitrix. However, they eventually realize that Ben is the only one who can save the world from the Highbreed, and allow him to continue.

In the Ben 10: Ultimate Alien episode "Hit Em Where They Live" where Carl is oblivious to the fact that Vulkanus, Charmcaster and Zombozo were a few feet away and about to attack him, and that Ben, Gwen and Kevin were battling them while he was putting a spare tire on his car. And Sandra was kidnapped by Zombozo, but is later rescued by Gwen as her Anodite form.

Magister Labrid

 * Jeff Bennett – Ben 10: Alien Force and Ben 10: Ultimate Alien (flashback)

Magister Labrid is a plumber who appears in the two-part episode "Ben 10 Returns". He is an unspecified fish-like alien in a water-filled suit who was Grandpa Max's partner. He first appeared before Ben and Gwen when he thought that he stole the Omnitrix. He was taken down by Gwen as Magister Labrid thought that Ben was some kid who stole the Omnitrix. The three of them stakeout a weapons trade held by Kevin between the DNAliens and the Forever Knights. They managed to take down Kevin while the DNAliens and the Forever Knights got away. During the second fight with the Forever Knights, he was mortally wounded protecting Kevin which ended up damaging his suit enough to leak. Kevin states that he has some tape to repair it only to deny Kevin's request. Before he evaporates, he tells Ben, Gwen, and Kevin to complete their mission to stop the DNAliens. He also appears in the episode 'Moon Struck' in which Grandpa Max recalls meeting Verdona, his anodite wife, for the first time. In this episode, Magistar recruits Grandpa Max to the plumbers.

Baz-El

 * Rob Paulsen - Ben 10: Alien Force and Ben 10: Ultimate Alien

Baz-El is a Galvanic Mechomorph whose name wasn't revealed until "Vreedle Vreedle".

He is a pilot who crashed and has spawned a symbiotic named Ship to find someone who could help him; he wanted help from Ben because he thought he was a Plumber. Before he left, he allowed Ship to stay with Ben and Julie. In "Vreedle,Vreedle" where he hired the Vreedle Brothers to retrieve Ship for him without knowing the consequences, he appeared in the court where he lost the trial on who kept Ship.

Baz-El returned in Ben 10: Ultimate Alien, in "Eye of the Beholder", he was stealing crystals and been catch, however he reveals that he has a job scanning the atmosphere of various planets, and makes money on the side by stealing artifacts from the planets he scans which for purchase as part of his "retirement plan", is how he earned the scorn of the inhabitants of the planet. When Ship felt him being in danger, and attempted to go and save him, Ben, Julie, Gwen and Kevin followed. After Baz-El was saved, Julie, believing Ship was better with him, attempted to give him back to him, but Baz-El stated he was gonna sell him as a weapon, causing Ship do choose staying with Julie.

Verdona Tennyson

 * Barbara Bain - Ben 10: Alien Force
 * Juliet Landau - Ben 10: Alien Force and Ben 10: Ultimate Alien (Anodite form and Human form in "Moonstruck" flashback)

Verdona Tennyson is Max Tennyson's wife, mother of Carl and Frank Tennyson, paternal grandmother of Ben and Gwen, and also could see that she is great-grandmother of Big Chill's proliferation. She is an Anodite alien from the distant planet Anodyne, who Gwen inherited the powers and abilities of control and manipulate mana, the substance of magic and life itself. Like all Anodites, Verdona is a free-spirited being. Though sometimes acting more mature and grown-up, she mostly acts like a playful child. There is also another side of Verdona which is somewhat amoral and uncaring, for example when she almost destroyed Ben and Kevin when they first confronted her, were it not for the intervention of Gwen and learning who they really were and when she was willing to destroy her granddaughter's physical human body to release the Anodite lying hidden deep within her. They had meet in the beginning of the 1960s, probably in 1962, during President Kennedy's office. Verdona left Anodyne in an unspecified time and was brought to Earth by a robot alien called Synthroid who had captured her and want to use her to power his world. They crashed and landed in St. Louis where she met and fell deeply in love with Max after he saved her; and then they courted each other and married, during this time she hid her Anodite heritage very well and blended in with society. During their time together, Verdona always had to deal with Max's occupation as a Plumber which she knew very well yet kept the knowledge from him, prompting Max to always lie to her every time he left and eventually after a long, happy and yet somewhat distant relationship, they parted.

They had two sons together, Carl and Frank. However neither of them showed any signs of inheriting her powers and abilities. When they were grown up and out of the house, she returned to Anodyne; after so many years on Earth, Verdona wanted to get back in touch with her background. She once came back to Earth to see if any of her grandchildren had inherited any Anodite abilities and powers from her, but saw that none did. Only several years later, she found out that Gwen, her granddaughter had developed powers and abilities of her own. It should be noted that Big Chill is in fact Ben, which makes Big Chill's offspring Verdona's great-grandchildren but it is unknown if they even could inherit her powers and abilities or if the energy from of the Omnitrix will prevent them from having "the spark."

She apparently favors Gwen over Ben, due to the fact that he did not inherit any powers and abilities from her so she just put him aside, which was shown when she magically conjured tape on his mouth so that he could not speak, that was until after their final fight against each other did she see just how much Ben cares about Gwen, the two reconcile on good terms afterward. She also has an uncanny sense of humor that was passed on to Ben, although Ben inherited his grandmother Verdona's spirit, sense of humor, and overconfidence, he also inherited his grandfather's determination, adventurous and self-sacrificing attitude. Also, she was shown to be a strict disciplinarian and shown to be serious when she needs to be, when Sunny went way out of line.

In "Ben 10: Race Against Time", Max told Ben that his paternal grandmother had passed away, although this might be a lie. As Ben was likely not ready for the truth about his grandmother being an alien yet as he was ten at the time.

She appears first time in "What Are Little Girls Made of?" when she explained everything to Gwen about her alien inherited, and offered Gwen to come back with her to Anodyne to reach the full potential of her powers and abilities (which would require seventy-five years), but Gwen had refused the offer. Verdona then shed her human body, revealing her true Anodite form, and thought that Gwen was too young to make her own decisions and decided to destroy her human body to free the dormant Anodite inside, but the two boys' stepped to defend Gwen. After a brief battle Gwen explained to her that she would rather stay on Earth with her friends and family, Verdona then tells Gwen that Max should have been an energy being like them, expressing her deep longing for him and that her desire to take Gwen with her could be just a front to fill the void in her heart. Verdona then claimed to return every so often to see how Gwen is doing.

Verdona returned in "Girl Trouble", where she was able to overpower Sunny, who was attacking Gwen, and she took Sunny and her boyfriend Antonio back to their home planets and allow their parents to decide on their punishment.

Natalie Tennyson

 * Juliet Landau - Ben 10: Alien Force and Ben 10: Ultimate Alien

Natalie "Lili" Tennyson is the mother of Gwen Tennyson, the aunt of Ben Tennyson, and the wife of Frank Tennyson. She looks like Gwen, with shorter hair. She appears first time in "What are Little Girls Made Of" when Verdona comes to Earth to visit Gwen and Frank. She has shown to be displeased with the heritage of Verdona. Lili doesn't seem to be particularly too fond of the Tennyson family, as she is usually complaining about them by saying their not as "formal" as her side of the family, possibly due to the fact that some of them are not completely human. She also said that Ben has bad table manners while castigated her father-in-law's fashion sense. She was also seen to have disagreements with her mother-in-law Verdona, making piericing stares at each other at every given opportunity. This animosity between the two is yet to be explained.

She appears later in the "Ben 10: Ultimate Alien" episode "Girl Trouble" where her niece Sunny stays with them for awhile despite Gwen's objections. She later reappears in "It's Not Easy Being Gwen," where she has Gwen help out with writing and mailing out letters to her side of the family for a regal-like party. She shows in this episode that she is as fond of Ben and Grandpa Max as Verdona, noting that Max's food is inedible and Ben doesn't have the best table manners.

Magister Prior Gilhil

 * J.K. Simmons - Ben 10: Alien Force and Ben 10: Ultimate Alien

Magister Prior Gilhil is a Plumber. He first appears when he encounters Ben, Gwen, and Kevin. Seeing as he hasn't considered the Highbreed a threat, he tells them to not get involved with the Plumbers. Darkstar later tips him off to a fight between Ben Tennyson and a Highbreed Lord, and he also ends up captured by Darkstar. After Gwen and the DNAliens defeat Darkstar, Magister Prior Gilhil made them honorary plumbers and then arrested Darkstar.

Magister Prior Gilhil reappeared in the episode "Escape From Agreggor" where in a flashback; he ended up answering a distress signal coming from Aggregor's ship. When he finds the five captive aliens during an inspection, he ends up knocked out by Aggregor. Magister Prior Gilhil was actually killed by Aggregor during his inspection which also explained how Aggregor was in his outfit when he recaptured Galapagus.

Reinrassic III

 * Richard McGonagle – Ben 10: Alien Force

Reinrassic III also called Reiny by Ben, is a Highbreed who is the seventh son of the noble Highbreed house of Di Ralla and direct descendant of the pureblooded High Order of Rassect.

Ben was forced to work with him while trapped on the desert planet Turrawuste, though they needed each other to survive (indeed saving each other on multiple occasions), Reinrassic showed the typical Highbreed hatred of who they wrongly call "lesser species", forcing Ben to walk ten paces behind him and insulting him constantly, even yelling at him for touching him while saving his life, Reinrassic eventually lost his hand saving Ben from a Dasypodidae, resulting in Ben reattaching it as Swampfire, much to the Highbreed's surprise. Eventually they made it to the teleporter, but due to him forming a friendship with Ben, he banishes himself to Turrawuste, believing himself tainted by him.

He returns playing a brief but important role in the final battle with the Highbreed, saying that they can live with other species in peace, stopping the Highbreed invasion and becoming 'Highbreed Supreme'. He later appeared trying to convince an awakened Highbreed officer to shut down a fail-safe weapon. The Highbreed at first did not believe him because of his green arm, but believed him when Reinrassic showed that their imperial seal was tattooed on his palm. After the fail-safe was destroyed, aid Ben to stop a Highbreed Failsafe weapon left over from the war, which had been activated by Highbreed Officer who was unaware the war was over.

Elena Validus

 * Alyssa Diaz - Ben 10: Alien Swarm
 * Tia Texada - Ben 10: Ultimate Alien

Elena Validus is the daughter of ex-Plumber who appeared and had a large role in the live-action film, "Ben 10: Alien Swarm". According to the movie, she hung out with Ben and Gwen. During this time she and Ben became close, he helped her join the school soccer team, speaking up for her when the other players wouldn't let her join and eventually became the team's MVP. She was Ben's first major crush, but she was force to leave Bellwood after her father Victor Validus was caught stealing alien tech from the Plumbers (Max never told Ben or Gwen why Elena and her father moved away). She eventually discovers her father had been taken over by the Hive Queen and seeks help from Ben and the Plumbers. As Nanomech, he goes into her dad and he kills the Queen, who controlled the Nanochips. Elena's father was freed, but apparently died shortly after the events of the movie.

Elena returns in the Ben 10: Ultimate Alien episode "Revenge of the Swarm", where she is shown studying the remaining Nanochips. After meeting with Ben to discuss a strange series of events involving Nanochips, Elena begins to display a disturbing attraction to him, which eventually leads to her kidnapping Julie in an attempt to ruin her relationship with Ben. When Ben finds Julie bound and gagged inside one of Elena's locked rooms, Elena goes berserk and reveals that the Nanochips she had been studying had taken over her body. After nearly killing Ben, Elena eventually regains control of her body long enough to seemingly commit suicide by walking directly into a Nanochip-destroying force-shield that she had developed. Though Julie attempts to comfort Ben by telling him that the real Elena had likely died a long time ago, Ben tells her that he thinks that a part of Elena must have survived long enough to save his life. However, some nanochips start to reactivate themselves after Ben left.

Unlike other Plumber's Kids, Elena is completely human, and has not special powers (at least in her first appearance). However, she is a capable fighter and an exceptional martial arts (skilled in both armed and unarmed combat). According to Ben she is also great athlete, becoming their school Soccer team's "Most Valuable Player". A Galvan Plumber instructor also mentioned she was one of his best students, and might have become a great Plumber. While processed by the Queen, she displayed the ability to transform into a full size Nanomech/Human Hybrid, with the powers to control the Chips and shape them into what ever shape she pleased.

Victor Validus

 * Herbert Siguenza - Ben 10: Alien Swarm
 * Brian George - Ben 10: Ultimate Alien (clones made by the Nanochips)

Victor Emilio Validus is the father of Elena and an ex-Plumber, and appears in the movie "Ben 10: Alien Swarm". He is the former pupil of Max Tennyson, who planned on passing command of the Plumbers to Validus and retires. However, Validus was discovered stealing alien technology (a serious violation of Plumber regulations). Feeling deeply betrayed by Validus, Max did not believe him when he explained that the alien technology he stole was in reality an alien species known as the Hive.

Prior to the movie Validus was studying the chips to find a weakness. During his studies he became host to the Queen of the hive, using his plumber knowledge the queen upgraded the chips and later used his body to mass produce the chips

Victor reappears in Revenge of the Swarm. He was presumed dead, his cause of death was unknown, it could be that he sustained some sort of cancer or disease which could be a result of being the host to the Queen which later claimed his life and simply that he had a bad health; which ended up being true when Gwen sensed him underground in the cemetery. His daughter, Elena, found some of the Nanochips and studied them. It turned out that she was being controlled by them, and could make them shape shift into anything.

Colonel Rozum

 * John DiMaggio - Ben 10: Ultimate Alien

Colonel Rozum is a United States Air Force officer with access to high profile information, even about the existence of the Plumbers, and has personally known Max Tennyson.

He first met Ben and the team in "Fame", where he was stationed at a base in Florida overseeing the construction, and later investigating the theft of the high powered rocket engines being developed by NASA to advance Earth to interstellar travel, using an experimental engines use a form of controlled nuclear explosion as a means of propulsion they were targeted by Bivalvan.

He returns in "Ultimate Aggregor", Rozum is given the case and is aware of what the government considers to be a failed time travel experiment, the Paradox Project, using an Entropy Pump to generate a weakness in the fabric of space-time allowing travel through time. Rozum had frustrated when Ben's team already know about the project, due to it taking him years of hard work to gain the clearance necessary. He wanted their help to stop Aggregor from using the Entropy Pump, giving his military strength to assist them should they need. It is in this encounter that he reunites with Max Tennyson (which may have been from Max's days as an astronaut given Rozum's connections to NASA) and meets Professor Paradox for the first time, where initially refers to Rozum as Major, a rank below Colonel implying that in the future Colonel Rozum could possibly be demoted.

He also appeared again "Prisoner Number 775 is Missing" when area 51 was attacked. Max was outraged to find out that Area 51 was a prison for any aliens that had been caught by Rozum and the military. One of the Prisoners escaped, and attempted to get revenge on Rozum for his unjustified decades of imprisonment that cost him the life of his family by targeting Rozum's family. After Prisoner 775 was defeated by Ben and taken in by the Plumbers, Rozum showed no remorse over the situation of the prisoner, declaring that he was serving his country and planet, severely putting a strain on his relationship with Max and the team.