5. RO-MAN IN ROBOT MONSTER (1953)

Close your eyes and think of the scariest monster you could ever possibly imagine. OK, now open your eyes. Is that monster nothing but a dude in a gorilla costume wearing a space helmet? Of course not, because that would just be downright silly. But the filmmakers behind this little film gem called Robot Monster didn’t think that way.

Why does the robot look like a gorilla? And why would a robot need a space helmet? None of these questions really matter because it's revealed that the whole thing was just a dream by the end of the movie.