Gearmo

Gearmos are robot allies that appear in Super Mario Galaxy. Most Gearmos live in the Toy Time Galaxy. Gearmos can be also found in the Buoy Base Galaxy, the Battlerock Galaxy, the Dreadnought Galaxy, and the Grand Finale Galaxy. A green one is also controlling the Engine Room.

Two Gearmos holding magnets attached to metal sticks are shown in the game. They are in charge of keeping the ammo depots in the Battlerock Galaxy and the Dreadnought Galaxy clean. They ask Mario to help them by throwing Bob-ombs at the garbage. It is possible that both Gearmos are the same, since both are green.

Most Gearmos are irritable neat-freaks. The Gearmo with the magnet becomes furious at Mario if he does not complete the Bob-Omb Challenge. Another one gets angry at him for destroying a giant weight holding down a tower, and another warns Mario not to let it catch him littering.

Gearmos have a large gear inside the back of their heads. If Mario jumps on the gear, it pops out, and falls back into place. Gearmos are capable of moving without the gear, suggesting that the gear has no real purpose. This may also indicate that Gearmos are living beings rather than robots. Further proof of this is the fact that, if the player gets zero purple coins in the Battlerock Galaxy, the Gearmo at the end will refer to herself as "this old iron lady", indicating Gearmos have separate genders, despite being iron robots.

Gearmos do return in Super Mario Galaxy 2, with the same purposes as in the prequel. Also, there are two Gearmos (gold and silver), which will show up on the Starship Mario, after Mario completes their objectives.

Trivia

 * Gearmo could possibly be a pun on the name Guillermo.