The secluded beach where Mario surfs and the kids play is taken over by Rad Tad and his group of Surf Dudes

Wally is in a predicament with Johnny Price, a boy who constantly plays practical jokes on him, Denver uses his magic eggshell to bring Wally back to a time where he was torment by the Pteranodon, causing Wally to find a solution to his predicament and befriending Johnny Price.

Denver and the group deck out in wild caveman attire and form a rock group, B.C Rock, to compete in the city wide talent contest, as does Freddy Facknitts (by forming a group of robots called Roborock). However, Dr. Funt and Morton Fizzback kidnap the robot band and Denver and the gang must rescue them.