Xenomorph

In Metroid Prime Hunters: First Hunt, the Survivor mode's description states: "Survive as long as you can against creatures growing in ferocity. Exterminate the Xenomorphs before they exterminate you." Xenomorph refers to several creatures in the mode:

The Xenomorph description is yet another reference to the Alien film franchise, from which Metroid took much inspiration. In this case, it refers to the titular Alien creatures in the films.