10 Sci-Fi Horror Movie Aliens That Make Space TERRIFYING

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.