Mugman

Mugman is the deuteragonist of Cuphead. He is Cuphead's sensible younger twin brother and, like the rest of his family, lives on Inkwell Isle. He is controlled by the second player and can join or leave the game at any time. Due to his deuteragonistic role, Mugman formerly could not be controlled by the first player. However, as of the update in April 2019, the first player can choose to play as Mugman instead of Cuphead, making it so that Mugman won't have to be controlled by the second player.