Teenage Cave Man (1958)
Robert Vaughn stars as a white 25-year-old teenage caveman with styled hair who seeks to discover what is in the uncharted jungles beyond his tribe's campsite. It is against the Word (and the Word is the Law), but he breaks it anyway. Soon he discovers a strange creature which kills with its touch. Written by Jonah Falcon
Roger Corman directed, so you know that this is going to be a fun riff.
STAR WARS STINKS commented
This was riffed on MST3K. It's on YouTube, last I checked. :)