Spaceship (1983) Leslie Nielsen, Patrick Macnee, Gerrit Graham, Cindy Williams, Bruce Kimmel

Aka Naked Space. Aka The Creature Wasn't Nice.
When the spaceship Vertigo stops to explore a previously unknown planet, the crew finds an unrecognized dollop of protoplasm and takes it aboard ship to return it to earth for analysis. On board, lifeform expands into an oozing person-eating monster which communicates primarily by means of a Vegas lounge act. The crew is gobbled up one after another until the few remaining crewmembers come up with a plan.