10 Sci-Fi Horror Movie Aliens That Make Space TERRIFYING

Xenomorphs, Xenomorphs, Xenomorphs... where to begin?

First seen in Alien, Ridley Scott's 1979 sci-fi horror cornerstone, the creatures and their extended family (see: Deacon, Neomorph, Predalien) have since plagued the big screen in no less than eight feature films - and several on fittingly doomed productions.

Aggressive and violent hive-minded hunters who seek only to propagate and annihilate, the Xenomorphs tear through any and every lifeform they encounter, leaving entrails and the occasional sub-species in their wake.

Xenomorphs are destructive by design, from cradle to the grave. Beginning as eggs laid by a Queen, they spawn Facehuggers (much as they sound), which impregnate a host body with Chestbursters, which then, after violently bursting free from their host's chest, go out into the world to become their own person.

Their genesis stems from god-like intergalactic entities, The Engineers (though we all know the true mastermind of this horror was the late HR Giger), who sought to create a living, breathing, biological equivalent of the atom bomb, engineered to wipe out unruly populations and maintain balance throughout the universe. Or, at least, that was the theory. But even they failed to see the horrors of their own creation.

With the help of several semi-assimilations, where the original creatures took on aspects of their reproductive hosts, and the tinkerings of external players, such as the human-created android David, the species have mutated, grown and become the Xenomorphs we know and fear today.