The Bath Boy Gang leader is the leader of the Bath Boy Gang in the episode "The Vault." He threatens Princess Bubblegum in the early days of the Candy Kingdom. He sends Shoko on a mission to steal Princess Bubblegum's amulet with the promise of making her a member of the Bath Boy Gang if she succeeds and death should she fail. It is unknown what happens to him or his gang.
He is an overweight yellow humanoid who spends all day in a bath. He wears a towel on his head and has a pink facial mask with eye cucumbers, which he eats.