Alien necromorphs are very similar in size, appearance and behaviour to alien versions of the human-based brutes, standing at roughly 7-8 feet and with a thick, armoured exoskeleton. However, whereas brutes are multiple human remains fused together to create one bloated body of bone and calcified flesh, alien necromorphs are made of a single alien corpse and appear skeletal. The head of alien necromorphs is truly strange as it appears to be mostly bone, with the infected alien's skin pulled taut against it. Similar to pregnants, the stomach houses another type of necromorph, crawlers. The alien necromorph actually looks a lot like the alien skeletons that can be found on Tau Volantis.
As stated above, alien necromorphs behave like brutes, charging at their enemies, using their mass as a weapon. However, alien necromorphs also have the pregnant's ability to burst crawlers from their stomach when killed or shot there. When attacking, this type of necromorph emits an eerie, high-pitched whistle, courtesy of the resonating chambers of it's host body.