metroid (creature)
Titular beastie of the Metroid video game series. Typically a floating, green, jellyfishy being with two sets of fangs and four red nuclei. However, this tag may also be applied to its advanced forms.
Developed on the planet Zebes, with the planet SR388 being their natural environment. Their prey ranges from just about anything that moves, but they are the only natural predator of X Parasites.