Geemers are enemies from the Metroid universe. Geemers are semi-spherical mollusks with spikes along their backs. They originally only appeared in two colors: yellow and red. Geemers are only capable of walk in set patterns, meaning that they can't directly attack other characters, the only way the characters can get damaged by them is by simply touching a Geemer.
Geemers appear as common enemies in Smash Run.
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.