Roger Corman‘s Teenage Caveman (’58) has been a joke movie for decades. Long ago Robert Vaughn (who died at age 77 in 2016) called it “the worst movie ever made”, and it may still be that.
But remember that it had a decent third-act twist: the prehistoric world of the film was actually a post-nuclear holocaust realm. In short, it ended like Planet of the Apes.
Vaughn obviously didn’t look teen-aged in the film. He was around 25 when it was shot, and looked 29 or 30. He would’ve been convincing if the film had been titled 20something Caveman With a Mortgage and a Baby On The Way.
