10 Famous Movies You Didn't Realise Were Already Other Movies

10. Alien (1979) Is It! The Terror From Out Of Space (1958)

Alien It

Alien is often considered to be one of the best movies ever made, given the way it seamlessly blends sci-fi and horror, and there's that bit where Sigourney Weaver is walking around in her underwear. That's a good bit. The movie itself concerns the crew of a space vessel who intercede a transmission on a lone planet, decide to investigate, and accidently bring an alien on board, which proceeds to hatch into a creature of terrifying force and murders them all. It would be a wholly original plot... had it not been the premise of another movie entirely. Yes, Alien owes its allegiance to B-movie from 1958, called It! The Terror From Beyond Space (don't laugh) which isn't as well-known or iconic or even as good as Alien, but does cling to the same story as Ridley Scott's more violent and therefore better-liked picture. So the idea of a spaceship's crew landing on an uncharted planet and picking up an alien by accident? It! An alien using the vents to navigate the ship, and even coming face to face with a blowtorch in one scene? It! The alien being sucked out into space for the finale? Alien! No, I'm kidding - that was It!, too.

All-round pop culture obsessive.