From the Super Mario Wiki
Caveman Land is the main setting for the The Super Mario Bros. Super Show! episode "Quest for Pizza". It has a wide range of ecosystems, featuring geographical features such as deserts, waterfalls, rainforests, caves and more. The land has a wide range of wildlife as well. Species range from the primitive version of Toads and Cave Mushrooms to a Cowazaurus. The character Mugga makes her first appearance here, aiding the Mario brothers in their quest.