A Cave Man is the idea most have of what prehistoric humans looked like. A cave man appears in the episode An Ice Girl for Boomer.
The Cave Man had an interest in Un-gela. She was his date to the luau (at first) so he ran there and, to get revenge on Boomer, captured Rebecca, Boomer's date at the time. He took her to the roof of The Castle. Boomer made Un-gela realize how much the Cave Man liked her, and she ran up and persuaded him to let go of Rebecca. Rebecca fell and knocked Boomer down, but they both landed in the bubble wrap Mikayla had laid down in the plaza. (An Ice Girl for Boomer)