Punk is a recurring non-playable character Trevor games. He is a chipmunk wearing a blue baseball cap with a red brim.
Punk blocks the player's path saying "a toll is required" to get past him. If the player has the bomb given to them by Whitey in their inventory, Punk will accept the bomb as a "toll" and let the player through. In the area directly after, Punk appears again and offers to sell the player back the bomb that he was just given in exchange for "fifty monetary units."