Cylon Raider

The Cylon Raider is the standard starfighter used by the Cylons, in the various Battlestar Galactica movies and television series. Cylon raiders are used as the main line of defense for Cylon Basestars.

Original series
The Raider in the original series is an exceptionally powerful fighter/attack craft employed by the Cylon Empire and carries much more formidable armament than the weapons on Colonial Viper fighters (two directed energy weapons and provisions for internal bombs). A Cylon Raider carries a crew of three centurions (commander, pilot and co-pilot). The commander sits on a slightly elevated seat between the two pilots and issues orders. Raiders frequently make suicide attacks on enemy capital ships, typically attacking the fighter launch bays. Although a typical Basestar holds far more Raiders than a Battlestar has Vipers, this advantage is often negated by the human ability to improvise and adapt to changing combat situations. In the episode "The Living Legend", Baltar commissioned a personal fighter to take part in a battle. It is used to transport him (not unlike Colonial shuttles).

1980 Series
A larger 'super' raider was depicted in the sequel series Galactica 1980.

Battlestar Galactica (2003, 2004–2009)
In the 2003 reimagining of Battlestar Galactica, the Cylon Raider is the main attack fighter used by the Cylons, participating in the destruction of the Twelve Colonies and later actions.

This fighter is very different from the previous, piloted Raider used during the Cylon War (the Raider from the 1978 series). The new Raiders are cybernetic in nature: the ship is actually a living creature. Just like the humanoid Cylons, the Raiders are also capable of being "reborn" into new Raiders after having been destroyed. This is done so that new, replacement Raiders do not have to be trained, meaning that experienced combat "pilots" that have been killed are quickly available for duty again. This provides the Cylons with a distinct tactical advantage in the amount of battle-seasoning a Raider will have over a replacement Viper pilot; in essence, every time a Raider is destroyed, it is reborn slightly improved having "learned" through each Death/Downloading/Rebirth life-cycle it undergoes. . Raiders can also perform riskier, but more devastating attacks on the Colonials, including but not limited to, kamikaze-style attacks.

The Raiders have many weapons, including conventional and nuclear missiles as well as kinetic energy weapons. They can transmit a computer virus to a Colonial vessel using the Command Navigation Program (CNP), rendering the Colonial vessel inoperable. When transmitting the virus, its red eye activates and oscillates to the left and right repeatedly.

The Cylon Raider is also capable of making FTL jumps. After a Heavy Raider was captured by the Battlestar Galactica, its FTL drive system was discovered to be more efficient than those on the Colonial vessels. It could travel the distance of Kobol to Caprica in less than 10 jumps (compared to the estimated 120 jumps the Colonial fleet would take)

It is capable of atmospheric flight, as was its predecessor, and is far more maneuverable in spaceflight than the previous Raider, likely due to upgraded thrust-vectoring systems. It is likely, due to the design, that it would be less maneuverable in atmosphere than the Colonial Viper due to its less conventional lifting body configuration and may have been designed to be unstable in all fight envelopes - with the slack taken up by computer control - as is common with many fictional and non-fictional fighter designs (A good example of this would be the Eurofighter Typhoon).

Evolution
Sharon Valerii has stated that the Cylon Raiders are very much like trained animals with basic thought and survival instincts. They also feel pain and trauma in the experience of death.

During battle in the episode "He That Believeth in Me", a Raider scans a Viper piloted by Samuel T. Anders. The Raider, possibly believing Anders to be one of the Final Five Cylons withdraws, along with the other Raiders who refuse to fight. This act leads the Twos, the Sixes, and the Eights to believe the Raiders have developed free will. The other models believe the Raiders have exceeded their original programming and vote, along with a single Number Eight, Boomer, to have the Raiders reconfigured back to their basic mode. The Twos, Sixes and other Eights protest vehemently and in retribution remove inhibitor modules from the Centurions, effectively giving them independent thought. The Centurions become angered by what the other models have considered the lobotomy of the Raiders and seek retribution on the models who voted for it.

Kara Thrace's Cylon Raider
In the episode "Act of Contrition", Kara "Starbuck" Thrace shot down a Cylon Raider, but her Viper was damaged in the process and she was forced to eject, landing on a nearby moon. In the course of the following episode, she located the downed Raider and discovered its biotechnological nature. Experimenting with the various systems, she eventually managed to fly it back to Galactica, having previously written her callsign on the wings using adhesive tape, so that Galactica's fighter patrols wouldn't try to shoot her down - a tactic that was not entirely successful, as a brief dogfight ensued with Lee "Apollo" Adama before he got close enough to read it. The Raider was brought back to Galactica to be studied by Chief Tyrol and his team.

In the first season finale, "Kobol's Last Gleaming," Thrace was ordered to use the Raider to transport a nuclear bomb on a mission to destroy a Cylon Basestar in the orbit of Kobol. However, President Roslin asked her to use the Raider's FTL capabilities to return to Caprica to retrieve the Arrow of Apollo instead. Disheartened by the fact that Commander Adama had lied to her and the rest of the crew about Earth, she pretended to embark on a final test mission, but jumped away to Caprica.

On Cylon-occupied Caprica, Kara fought and killed a copy of Number Six in the Delphi museum. Kara successfully retrieved the Arrow and met up with the stranded Galactica crewmember Karl "Helo" Agathon and a copy of her crewmate Sharon "Boomer" Valerii, revealing her to be a Cylon. Sharon (a Number Eight) fled in Kara's Raider. Sharon later returned minus the Raider (its fate is never shown or explained), but later stole a Heavy Raider, using it in an attack on several Centurions, and then transported all three back to Galactica.

Scar
Appearing in the episode of the same name, Scar was a particularly vicious and elusive raider identified by a gash on the side of its "face". Using highly effective hit-and-run, ambush and divide-and-conquer tactics, Scar repeatedly ambushed and destroyed Colonial viper patrols during mining operations in an asteroid field.

Sharon Valerii pointed out that given the (previously unknown) ability of Cylon raiders to "resurrect" like their humanoid counterparts, Scar's remarkable combat skill was likely due to having fought (and/or being destroyed by) Colonial pilots and learning from these previous encounters. Valerii also suggested that due to the lack of a nearby Cylon Resurrection ship, Scar would be more difficult to beat, given its newly added fear of death.

Eventually the raider was hunted down by Starbuck and Louanne 'Kat' Katraine. Kat destroyed Scar after Starbuck lured the raider into her sights. Kat managed to destroy one of Scar's wings, causing it to crash into an asteroid which destroyed it completely. As the resurrection ship had previously been destroyed, its death was permanent this time.

As a final note, Valerii implied that Scar was Kara Thrace's Raider (see above). This could lead to the notion that Scar had a vendetta against the Colonial pilot. However, the truth of this claim has not been addressed in canon thus far.