25 best horror movie monsters

25. Xenomorphs (Alien)

Let’s just address the terrifying, killing-machine elephant in the room before it eats us, okay? Because no accounting of horror movie monsters would be complete without the terrifying xenomorphs.

If you’ve somehow missed the boat when it comes to the most terrifying space creature of all time, here’s a quick primer. We first encounter the xenomorphs in the 1979 classic, Alien, directed by Ridley Scott. The doomed crew of the Nostromo, a commercial hauler, are awoken from their interstellar sleep. They’ve received a mysterious transmission from a nearby planet, meaning that there may be alien life attempting contact. The crew is obliged to respond.

Once on the surface of the planet, executive officer Kane (John Hurt) gets into a close encounter with a “face hugger”. The arthropod-like creature latches onto his face and everyone naturally freaks out. Though warrant officer Ripley (Sigourney Weaver) tries to maintain quarantine, she’s overruled by the ship’s science officer, Ash (Ian Holm).

Without revealing too much, this series of events leads to a bad xenomorph infestation on the Nostromo. And though we only see one such monster, it’s enough to give you nightmares for the week. Designed by Swiss artist H.R. Giger, the alien is at once repulsive and beautiful. It’s all strange, organic forms covered by a sleek, black exoskeleton.

And when you’re one of the unfortunate crewmembers who gets an up-close look at the xenomorph, you may briefly notice its double set of jaws and lack of eyes before you’re consumed.

The xenomorph is a masterpiece of inhuman menace. There’s no reasoning with a xenomorph, no appealing to its sense of morality or self-interest. It simply wants to reproduce. No matter how much you scream, you’re only a vessel to the xenomorph.