Robot Monster (1953)

Synopsis
A young boy named Johnny (Gregory Moffett), who is fascinated with outer space, is on a picnic with his widowed mother (Selena Royle), older sister (Claudia Barrett), and younger sister (Pamela Paulsen), when he meets a pair of archeologists (John Mylong, George Nader) exploring a nearby cave. Later, as the family sleeps, he has a dream -- that the Earth has been attacked by a alien named Ro-Man, using the "calcinator death ray," and that he and his family (with Mylong and his mother now married) and scientist Nader are the only survivors. They try to elude capture by Ro-Man (played by actor George Barrows, in a gorilla suit with a diving helmet), who turns out to have some very human failings despite his computerized mentality -- several members of the family are killed, but Ro-Man is destroyed by his controllers when he decides he'd rather experience human emotions. Then Johnny awakens and realizes that he's been asleep, having fallen down near the cave where the two men were digging. The archeologists join the family on their picnic and leave the cave, Johnny now convinced it was a nightmare. After they leave, the image of Ro-Man appears, wandering out of the cave, his arms grasping toward the camera as the film fades out. ~ Bruce Eder, All Movie Guide