It! The Terror from Beyond Space (1958) starring Marshall Thompson, Shawn Smith, Kim Spalding

Synopsis of It! The Terror from Beyond Space

When his crew is brutally murdered on a Mars expedition, Commander Carruthers becomes the prime suspect. Taken into custody and facing a court-martial back on Earth, he discovers that the real killer is a grotesque monster.  “It” has stowed aboard the earthbound ship. But the indestructible creature had already begun a harrowing in-flight rampage, knocking off the members of the crew, one by one. Now, as the spaceship heads home toward a panic-stricken Earth, the remaining crew must find some way to stop the unstoppable…”It! The Terror from Beyond Space”