Ro-Man, an alien robot who greatly resembles a gorilla in a diving helmet, is sent to earth to destroy all human life. Ro-Man falls in love with one of the last six remaining humans, and struggles to understand how his programming can instruct him to kill her while his heart demands that he can't.
George Nader
as Roy
Claudia Barrett
as Alice
Gregory Moffett
as Johnny
Jack Mylong-Münz
as The Professor
Selena Royle
as Mother
Pamela Paulson
as Carla
George Barrows
as Ro-Man the Monster / Great Guidance
John Brown
as Ro-Man / Great Guidance (voice)
