Weasel is a character from Marvel Comics, who is a friend of Deadpool.
In the Deadpool movies, he was portrayed by T.J. Miller, who also portrayed Gene in The Emoji Movie.
At some point, Weasel met and befriended Wade Wilson before putting him in a series of organized bar fights known as the "Deadpool". After Wade was diagnosed with cancer, Weasel comforted his friend by joking about his inevitable death. In desperation, Wade underwent an enhancement program, gaining a healing factor but getting disfigured in the process. Wade would then tell Weasel about his experience in the program and his desire to seek revenge against Ajax, who had been responsible for disfiguring him. After getting an idea, Weasel convinced Wade into becoming a superhero known as Deadpool, the name inspired by the bar's matches. Later, Ajax and Angel Dust arrived at the bar in search of Wade Wilson, briefly threatening Weasel before discovering and targeting the mercenary's lover, Vanessa Carlysle. After learning of this, Wade took Weasel with him to find Vanessa, only for Ajax to promptly kidnap her. Determined to save his love, Wade went to Blind Al's house and armed himself for the impending confrontation, to which Weasel opted out of.
Weasel first appear when Wade is in the bar depressed for Vanessa's death and Weasel try to console him with the help of Wilson's taxi driver Dopinder who now work in the bar, in risponce Wade tryed go suicide himself failing due to his immortal status.
Later Weasel help Wade to recruits member for a superhero team named X-Force to stop the time travel bionic soldier Cable to kill a young mutant named Russell aka Firefist, they recruits Domino, Bedlam, Shatterstar, Zeitgeist and Vanisher, however Weasel is captured and tortured by Cable who asks him information on where his friends are going to bit Weasel just gave up the information since he did not want to hurt, so Weasel was free.
Later Weasel go to Blind Al's house where Wade is rigenerating his inferior body part after he was broken in two by Jaggernaut, Wade for now have baby legs during the inferior body parts rigenerations with Weasel, Dopinder, Blind Al (who accidentally touch his pene in regeneration) and Domino' s comical shocking reaction, then Cable arrive without they even accorgeus, when they find out who Cable is the there everyone point the pistols against him especially Weasel, Cable, despite was comically disgusted by Wade's baby legs, offered to Wade his alleance to defeat Juggernaut and stopping Russell from his first killing who would turned him into a killer who in the future would killed Cable's family, so Wade and Cable ally but at he condition who Cable will let Wade convince Russell to not becoming evil and them two, Domino and Dopinder goes to stop Firefist and to defeat Juggernaut.
Weasel opted out of the battle again and probably he is back to the bar after being leaved in Blind Al's house.