Geemer

A version of the Zoomer which, in Metroid Prime and Metroid Prime Hunters, is indestructible if shot by the Power Beam. When attacked in this fashion, it defends itself by protruding spines. The only way to destroy a Geemer in Metroid Prime Hunters is to shoot it with any of the six sub-weapons or a missile, and in Metroid Prime, to shoot it with a charged beam or missile. When scanned in Metroid Prime Hunters, the readout says: "A small but dangerous creature that exposes sharp spikes on its back when threatened. This scavenger is known to forage through human refuse and is an infamous pest on Zebes." In the side-scrolling games, Geemers are merely able to take more damage before dying. They are red instead of black.

Artificial Intelligence

The AI routine is as follows: The Geemer begins by moving in either the left or right direction. When the Geemer encounters a vertical wall, it rotates by 90 degrees and walks up the wall it hit. Conversely, if the Geemer walks off of a ledge, it rotates -90° and walks down the wall. This allows Geemers to move in simple circles around a complex room or object.

There is a flaw in the Geemer AI in the original Metroid. If the object the Geemer is standing on is removed, the Geemer continually spins in place, as the AI is constantly rotating by -90°. This is fixed in Super Metroid, as the Geemer unceremoniously falls to the floor.

In Super Metroid, a Geemer of the ordinary blue/purple type is one of the first enemies encountered. It does minimal damage. When Samus Aran fires a Super Missile at a wall or ceiling, the resulting shockwave causes all Geemers in the area to fall off the ledge they were on.

Geemers are also seen in Metroid Prime, as three dimensional creatures resembling a turtle. They follow a very similar AI modified for three dimensional movement.