It! The Terror from Beyond Space (1958)

The first manned expedition to Mars is invaded by an unknown life form, which stows away on the rescue ship.

Director: Edward L. Cahn

Cast: Marshall Thompson, Shirley Patterson, Kim Spalding, Ann Doran, Dabbs Greer, Paul Langton, Robert Bice, Richard Benedict, Richard Hervey, Thom Carney, Ray Corrigan, Stuart Hall, Mike Morelli, Monty O'Grady, Bert Stevens, Pierre Watkin