Space: the final frontier. Where men go to die and a million horrific entities rule over a million more equally horrific planets - if the endless onslaught of extraterrestrial horror films are to be believed, anyway.
Science-fiction horror is an enduring genre, reinventing or redefining itself every decade or so, expanding as it goes, accommodating the desensitisation of viewers and pushing the boundaries of taste. From the soft-spoken indie to the big budget blockbuster, strange beings from outer space have crept, slithered, crawled and floated across the silver screen since the medium's early days.
Whether hulking, egg-laying queens or slippery fungal parasites, aliens come in all shapes and sizes, forms and substances, ready to tear your face off and chow down on your innards in a double-heartbeat. If anything is for certain, the majority of our intergalactic neighbours seem intent on corruption, assimilation or annihilation - and who's to deny them, if we go wandering so willingly into their midst? After all, how many Ripleys are there to Xenomorphs, how many Groots to Outriders, how many Nicolas Cages to purple mists?
These ten aliens will make space - yep, that beautiful dreamscape with little light, no oxygen and temperatures approaching absolute zero - a terrifying place that neither you nor Elon Musk ever want to visit (again?).
10. Killer Klowns
1988's The Killer Klowns from Outer Space took everyone's biggest childhood fear and made it homicidal and extraterrestrial.
Rather than adopting the form of the things they encounter, the Killer Klowns are pre-packaged and ready to clown from the get-go. Travelling the galaxy in something resembling a giant spinning top made from an inverted circus tent, the Klowns sport white faces, neon hair and lots of razor-sharp teeth. They are able to manipulate their own bodily dimensions, bring shadows to life and perform feats of scientific wonder akin to magic (see: jumping fifty feet in the air or piloting an invisible clown car at breakneck speed).
As if that wasn't enough, the Klowns have an arsenal of circus-based weaponry and tricks, with which to hack, chew and dismember their victims, but perhaps none more terrifying than Klownzilla, the monolithic marionette large enough to use an ice-cream van as a frisbee.