Galleom

Galleom is a boss that appears in the game, Super Smash Bros. Brawl. Galleom is a purple skinned monster in a robotic form. Galleom is first fought by Meta Knight, Marth, and Ike. After the battle, Galleom then takes a huge leap and lands near to where Wario was once turned into a trophy. However, the floor breaks from the impact of the landing and Galleom falls into The Ruined Hall. Galleom then sees Lucas and Pokémon Trainer, and fights them. After the second battle Galleom grabs Lucas and Pokémon Trainer and opens its cranium, revealing a Subspace Bomb. It launches into the air with them only having 15 seconds left.

Lucas uses PK Thunder to break off Galleom's arm, and frees them. Right before they land, they are saved by Meta Knight. Galleom, however, meets its end with an explosion. Later though, players must fight it again in The Great Maze. Although it was fought two times in the game, players only need to fight it once in the Great Maze.

Trivia

 * Galleom is not the first boss to fall through the top of a tall, circular building. In Super Mario Sunshine, the boss Petey Piranha causes the roof of the windmill which he is sitting on to crumble and collapse. Petey is then fought inside the windmill, much like Galleom is battle after falling into The Ruined Hall.