From the Super Mario Wiki
Cave People are native humans of Dinosaur Land who have appeared in many episodes of the Super Mario World animated series. The Cave People are generally rather short and stubby in appearance, often having long hair. The only notable Cave Person is Oogtar, who replaces Toad from The Super Mario Bros. Super Show! and The Adventures of Super Mario Bros. 3 (through Oogtar voice actor is the one who voiced Toad). Cave People appear to be somewhat dumb in comparison to present-day humans. Cave People resemble and are likely based on the prehistoric peoples of Earth.
Cave People are also known to inhabit Caveman Land, as seen in The Super Mario Bros. Super Show! episode "Quest for Pizza". However, only one Cave Person, named Mugga, was ever seen. The rest were all shown to be Cave Mushrooms, and were essentially primitive Mushroom People.
 Notable Cave People