A Geemer (sometimes spelled "Jeema" in Japanese, and likely pronounced similarly in English) is an evolutionary offshoot of the Zoomer family. Geemers roam many surfaces in search of food, and can cling to walls with their feet. When threatened, Geemers defend themselves by extending spines from within their bodies. They have been found on many different planets, including Zebes, Tallon IV and Bryyo.
In Metroid Prime, the Geemer is invulnerable to the Power Beam, Ice Beam and Wave Beam. Geemers in Metroid Prime look very similar to Zoomers but with three eyes. In Prime, they are located in the rooms Tallon Canyon, Root Cave and Transport Tunnel C. Geemers are also present in Metroid Prime Hunters, where they can be found in the Arcterra Gateway and Alimbic Gardens.
In the aforementioned games, Geemers can be killed with any other Beam weapon or a Missile. The main difference between the Geemers in the Prime games and elsewhere is the leg formation. Geemers of Prime, Hunters and Corruption all feature very small legs or feet that do not protrude far from the underside of the shell. Conversely, the other Geemers Samus encounters have longer legs with multiple joints.
In Super Metroid, a Geemer of the ordinary blue/purple type is one of the first enemies encountered. It does minimal damage. When Samus fires a Super Missile at a wall or ceiling, the resulting shockwave causes all Geemers in the area to fall from their ledges.
Interestingly, Super Metroid's code refers to Geemers as Zoomers, indicating that the "new species" was an invention of the translation team. Several other creatures changed names between the original game and Super Metroid, but only Geemers emerged as a separate species alongside the original in subsequent games.
Geemers return in Metroid: Other M as enemies in the Main Sector and the Biosphere. Hologram Geemers are also seen during the training sequence at the start of the game. They also appear in an ice form known as a Snomer throughout the Cryosphere. In this game they gain the ability of jumping and moving faster than they did in other games.In Metroid Fusion, the X Parasites have either infected or imitated most of the creatures in the BSL Station. The Geemers, being one of the many lifeforms kept in the station by researchers, were among those targeted by the X. The Geemer's DNA was manipulated by the X to create an altered variation of it: Geemer-X have elongated back spines, thick plating which quickly covers their entire body when shot at, and a different color than their natural counterpart.
Geemers were not known to exist on planet SR388, but the species must have members there to have been present on the BSL Station (as all of the Station's specimens originated on the planet).
In Metroid Prime: Federation Force, Geemers are found on Excelcion.
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 destroyed, 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, although that glitch can still be exploited if done with precise timing (the Geemer/Zoomer must be going onto or from the door to/from another surface and it will rapidly spin as if in the original Metroid).
In Metroid: Other M, the Geemers received an intelligence boost, and will actively follow Samus and roll at her, instead of just going around like they did in Super Metroid.
There is also a unique quirk involving Geemers in Super Metroid. In Crateria, there is a small enclosed room on the right side, close to the Wrecked Ship. It is visible on the map as a small rectangle surrounded by a much larger room. When Samus enters this room, a Varia suit-colored Geemer that is orange and has green on the tips of the spikes is visible above her. This Geemer follows a different pattern from normal Geemers, as it will match Samus' horizontal movements on top of the tube. This Geemer can be killed by the Wave Beam, Grapple Beam (jumping and grappling as soon as Samus hits the ceiling will cause the grapple beam to phase through the barrier) or Power Bombs, and the item dropped by it (usually energy or missiles, like any other enemy) can be collected via the Grapple Beam as well. Further, this particular passage can be approached from above, but when the player reaches it, the Geemer is absent.
"This organism excretes a mucus from its legs while crawling on the rocks. The yellow Geemer can be destroyed with two shots from the normal beam. The red ones are destroyed with four."
Super Metroid manual
"Geemers crawl on floors and walls."
"Not powerful, Geemers walk steadily around various surfaces in a repetitive manner."
Wall-crawling mollusk with retractable spikes
The Geemer is an evolutionary offshoot of the Zoomer family. When threatened, it extends lethal spikes and retracts its head deep into its armored carapace.
"Geemers can crawl along the ground, the walls...even the ceiling! Those spikes will hurt any fighter who touches them."
- These creepy crawlers from the Metroid series cling to any surface, even the ceiling. The spikes on their backs are painful to the touch, so be careful around them. In Smash Run they'll travel on the floors or ceilings, so borrow a page from Samus's book and take them out from afar.
- "If you spot one of these creatures from the Metroid series crawling along, do your best to avoid those spikes on its back. In Smash Run, they could be on the floor, or they could be on the ceiling. Either way, you'll get hurt if you touch them, so keep a safe distance and take them out with ranged attacks."
Animatronic Geemers are an enemy in the Metroid Blast attraction of the theme park. They are ground enemies that chase the Mii characters with the ability to walk over walls. They come in two types, single hit and 3-hit points. The 3-hit version can fire homing missiles. They must be shot in their weakpoint, which is their chest, resembling a power button.
A Geemer is also a prize. It is yellow, light blue and red in color. It is situated in front of Pikmin Adventure. When activated, its four legs come out of its round body (initially it resembles a spiked ball on the ground), it rumbles, pounces and tries to strike the ground with its legs, then twirls to the right and retracts its legs. Its description reads: "Geemers seem to crawl along harmlessly at first, but they'll spring at you if you get too close! Whatever you do, don't let them surround you. These lovable creatures can climb up walls, too!" The spring part, in Metroid games, only occurs in Other M.