From DYOS Wiki
That's a- these are like jellyfish or something

- Gordon Freeman (Mind of Freeman)

A metroid is a parasitic lifeform which is capable of absorbing any kind of energy. It usually hunts its prey by charging at it and attach itself to it[1], sucking out the energy from the target. The metroid has had a major role in the Metroid series as an antagonist and sometimes a protagonist (counting Super Metroid and somewhat Metroid: Fusion), and it seems to be a major target for the Space Pirates. It is believed to have been created by the Chozo for culling the Parasite X and for other means as well. A metroid has a high resistance to normal weaponry, but is weak against cold[2]. The metroids have an odd amoeba-like appearance with a big claw-like jaw; they often come in various appearances, which will depict special abilities such as the phazon metroid, which is capable of charging phazon energy to shoot out as a beam with lightning-esque attributes. Their spawns are currently known as miniroids. The most powerful known metroid so far is called Metroid Prime, which has been the main antagonist in up to 3 games in the series.


  1. Though a carry over from Half-Life, CivGeneral will actively refuse to let a Metroid attach to his head. A similar mechanic to why no headcrab attaches it'self to Gordon Freeman's head
  2. An exploit used by Samus Aran as well as Coruscanti cyro troopers

See also