D0g

D0g is a fictional character in the Half-Life series of video games, first introduced in Half-Life 2 in 2004. D0g is a hulking robot belonging to Alyx Vance, whose father, Eli, built to both celebrate and protect his daughter; Alyx subsequently upgraded the robot into its current form. His character provides comic relief during the series; his battle sequences are often comically exaggerated, such as taking on small enemy squads by throwing cars and trucks at them. His appearance as the first character seen in Half-Life 2: Episode One was influenced by positive fan reception.

Character design
Half-Life 2: Raising the Bar states that D0g's design underwent "relatively few changes" from his very first concept sketch; Valve artists were inspired by "classic movie robots," citing Robby the Robot from Forbidden Planet.

In video games
D0g's role in Half-Life 2 is to aid the player in tutorials—in particular, training in the use of the gravity gun—and lifting heavy objects the player cannot manipulate with out the gravity gun.

Reception
D0g was positively received as one of the best robot and sidekick characters in video gaming. In 2008, The Age ranked him as 50th top Xbox character of all time, stating, "Rather than just being functional, though, Dog manages to stick in your mind for act after act of incredible strength, agility, and bravery. He really is a man’s best friend."

That same year, he was one of the 64 characters selected by the staff for GameSpot's poll "All-Time Greatest Game Sidekick", but lost in the first round of user voting to Otacon (Metal Gear Solid). Also in 2008, GamesRadar ranked him as the gaming's best canine companion ("What’s better than a dog? A giant robot dog!"), calling him "the Jesus Christ of in-game dogs."

In 2010, Cracked.com included him on the list of six video game sidekicks "faster, stronger, more talented or just plain cooler than the actual hero," adding: "Why didn't they just program Dog to carry out the mission, rather than sending in Gordon with his sad little crowbar?" That same year, NOW Gamer included him among the 10 greatest video game robots, commenting: "He doesn’t speak, or even have a face, yet he has about a million billion times the personality of your average game character." Aso in 2010, Game Informer ranked him as the fifth artificial intelligence (AI) game characters of the decade, adding that "it’s hard not to love the robotic companion, just like a real canine." In 2011, UGO.com ranked D0g as the ninth best robot in video games.

That same year, Fandomania included him among the five most memorable video game robots, PopCrunch ranked him as the 13th best AI character in any video game, even as all the fight scenes that he is in are "just scripted to show off his coolness," and Joystick Division ranked him as the sixth-top robot in video game history, adding: "The unique and varied characters of Half-Life 2 make up a large part of its greatness, and D0G is right in the thick of it."