Buster's Prehistoric Ancestor resembles his descendant, but is huge, with one big unibrow, big teeth, and a red cloth.
He first appears dragging a large carrot to Babs' and Hamton's ancestors, and all three of them say they need a leader to bring everyone together and share their food. When Plucky (thanks to Montana Max's prehistoric ancestor whacking him with his club for being on his property) suddenly appears, he and the other cavetoons bow to him and Plucky is deemed the new leader of the group. After being amazed by Plucky's trick (a simple card trick), Buster's Ancestor tells him that he and the others need a name for their home. At first, Plucky want to name the land "Pluckyland", but the prehistoric citizens disapprove. Plucky is outraged, and he tells them that Acme Acres is a dumb name. The Prehistoric citizens like the name Acme Acres and decide to call it that. Later, he is seen filing Plucky's fingers while Babs' Ancestor is playing music, when Monty's Ancestor tries to keep Acme Acres for himself. He orders Dizzy Devil's prehistoric ancestor, a dinosaur, to eat Plucky. When Buster and Babs arrive, Plucky snatches the time machine from them, taking Dizzy's Prehistoric Ancestor with him. Monty's prehistoric ancestor destroys the prehistoric Acme Acres. Later, Buster and Babs encounter their Ancestors (in which Buster calls him his great-great-great-great-great-great-great-grandfather!), after mistaking them for their reflections in a mirror. Buster's and Babs' ancestors are told that Plucky was a fraud and vow to get their revenge on him if he ever returns to the past. That night, Buster and Babs tell their prehistoric ancestors about the 1990s. Their prehistoric ancestors tell them that Monty's Prehistoric Ancestor has taken over and they don't have a leader now to stop him. Buster and Babs tell them their plan. The next morning, after seeing Buster and Babs' prehistoric ancestors take over Max's cave and trash it, he agrees to fix Acme Acres. After Plucky returns, Buster's prehistoric ancestor and the other ancestors toss their fruit and vegetables at him for being a lousy leader.