Bouldergeist is one of the many bosses found in the Mario series. Its true form is a black ghost head. It has a rocky armor to protect itself.
Bouldergeist's first appearance was in Super Mario Galaxy. He then reapper in Super Mario Adventures II. He was one of the main bosses of the game, and was battled in the Luigi's Mansion level.
To the Galaxies
Bouldergeist will appear as a boss in RedYoshi's Universal Conquest. This will be the third game it has appeared in that takes place in space.
Bouldergeist reappears in this game as the boss of Boulder Drop Tower, in World 7: Great Stone Mountains
Super Smash Bros. Fusion
Bouldergeist appears as a stage boss in Super Smash Bros. Fusion, appearing on Ghostly Galaxy. While classified as a stage boss, he himself doesn't attack the fighters, instead raising platforms and pillars from the stone ground. He is damaged by destroying the stone platforms and pillars, with his attacks being quicker and the size of the pillars increasing. When he is defeated, he crumbles into the ground, which makes boulders rain from the sky for several seconds.
Bouldergiest is the Boss of Sky Station the 7th Board. He is sent with Tompanic to stop the player. He fights and id defeated like in Super Mario Galaxy.