Douchebag, or otherwise known as 'The New Kid', is the main playable character in South Park: The Stick of Truth. He is not a featured character in the animated series, and is only shown in the game. His only voiced line is spoken at the end of the game, "Screw you guys, I'm going home".
Not much is actually known about "Douchebag", except for the fact that his parents moved away with him from their previous home to South Park. It is hinted in the game that something may have happened in their previous home, for Douchebag's parents say that it is good he does not remember.
Douchebag is shown to be seemingly mute in the game, and only has one actually spoken line, which is at the end of the game. Cartman and others occasionally note that "Douchebag" is quick to make friends on Facebook.
Butters is the first character Douchebag can befriend in the game, and fights alongside Douchebag in the beginning. They are generally friendly towards each other, even though Douchebag doesn't say one word to Butters throughout the entire game.
Princess Kenny is the second character made available to fight alongside Douchebag, after Butters. After Douchebag finds a flower for Kenny, they become friends.
Stan is the third character made available to fight alongside Douchebag, after Butters and Kenny. When Douchebag is captured by the elves and ordered to recruit the goths by the King of Elves, Kyle, him and Stan try to convince Douchebag that Eric is using him to his advantage. Stan seems to respect and trust Douchebag as the king does.
Jimmy is the fourth character made available to fight alongside Douchebag, after Butters, Kenny and Stan. Eric, Douchebag and the others first meet Jimmy in their search of the Bard, who is Jimmy. Douchebag and Jimmy are not shown together much but seem to get along fairly well.
Kyle is the fifth character made available to fight alongside Douchebag, after Butters, Kenny, Stan and Jimmy. Kyle and Stan try to convince Douchebag that Cartman is simply using Douchebag for his own benefit, and Kyle tells Douchebag to recruit the goths and bring the goths to them instead of Cartman. Kyle says that he is trusting Douchebag to do what is right, and if he peforms an act of betrayal, he will tell everyone that Douchebag is a butthole.
Eric is the sixth character made available to fight alongside Douchebag, after Butters, Kenny, Stan, Jimmy and Kyle. Being the Wizard King, Eric welcomes the new kid, Douchebag, into his game, and does not seem to harbor any ill will for Douchebag. He even teaches Douchebag a special ability called Dragon Shout, where the Dragon Shout user releases an extremely powerful fart. Cartman frequently tells Douchebag to never fart on somebody's balls time and time again, as an oath.
Douchebag befriends Randy when he is abducted by aliens and is almost probed, but uses the Dragon Shout ability that Eric taught him in order to avoid being probed. Randy then asks him if this was his first time being probed and tells him that he has an incredible control of his asshole. Later, Douchebag saves Randy from the aliens and Randy says to consider him as a friend.
Douchebag saves Annie from a group of three bully girls, who took her Justin Bieber doll and taunted her with it. After Douchebag chases away the three bullies, Annie thanks him and they become friends. Later in the game where Douchebag needs to recruit girls, he goes to Annie first.