Bouldergeist is a character in the Super Mario series. He first appeared in Super Mario Galaxy. He is a boss that lives in Ghostly Galaxy. His name is a pun on the words 'poltergeist' and 'bolder.' He reappeared in Super Mario Galaxy 2 as the fourth boss in Boss Blitz Galaxy. He is made of boulders and shadows, and Mario has to hit him six times with Bomb Boos to kill him. After the third and sixth times, his true form will be revealed, which is a face with a red uvula hanging from it.