Boyon

From Wikitroid, the Metroid wiki

These little creatures are found on Zebes. They appear to be made of some sort of mucus substance. They will rest quietly at the bottom of a small hole and when something comes near, and will quickly leap from their hole repeatedly until the opposing creature is gone. These strange organisms greatly resemble the X Parasite as seen in Metroid Fusion, but these are not translucent, and do not contain glowing nuclei in their center.