Boy's dream about a hairy monster or alien turns out to be real [closed]

What is this 1950s sci-fi movie about a boy's dream?

I remember its ending where you are convinced that all the action in the movie turns out to just be a dream that occurred when a boy fell asleep at a picnic with his family. But then some kind of large hairy monster/alien comes out of a cave and you know that it really wasn't a dream.

science-fiction identify-this-movie

Best Answer

Most likely Robot Monster, (1953).

Ultimately the youngest family member, the son, wakes up after suffering a mild concussion, revealing that the film had presumably all been a dream. However, The Great Guidance is then seen coming out of a cave (three times in a row).

The monster was hairy:

The budget did not allow for a robot costume as intended so Tucker used his friend George Barrows who had his own gorilla suit to play Ro-Man. Tucker added the helmet.