Metroid (species)

Metroids are large and jellyfish-like creatures with quadripartite nuclei, and are the titular enemy in the Metroid series. They are capable of siphoning an undetectable life energy from any animal, generally causing the death of the victim in the process. This energy can also be siphoned from the Metroid in turn, allowing it to be used as a living power source.

In Super Smash Bros. Brawl, they appear as an Assist Trophy.