An Unnamed Predatory Species resembling reptiles were mentioned in Aliens: Theory of Alien Propagation. They were natural enemies of the Xenomorph.



These creatures were reptilian-like in appearance, with pale creamy skin and blazing orange eyes. They had clawed fingers and appeared to be quadrupedal. Several bony protrusions jut forth from their shoulders, legs, and tails. They could contend with a Xenomorph in combat and are shown clawing into and biting into their bodies, indicating that the Acid blood had no effect on them. Their own blood was black.

These creatures kept Xenomorph numbers in check. Instead of being above the Xenomorphs on the food chain of Xenomorph Prime, however, they seem to share the niche and compete, keeping each other's numbers in check.