Yameba

The Proto Metroids are failed clones of Metroids. Proto Metroids are blue and circular with green brains in the middle. Proto Metroids, like Metroids, can suck energy, and can join together to form stronger Proto Metroids. They reproduce very fast, but are also defeated bery quickly. Only by defeating all Proto Metroids in an area can a person truly eliminate them.