 By seeing Bamm-Bamm having fun with Dino, Barney thinks of buying a pet of his own. At the "Bedrock Pet Shoppe", Barney and Bamm-Bamm chose an unusual animal: a "Hopparoo". At home, Fred and Dino are chasing a mouse which frightens Wilma. The mouse goes to Barney s garage where Hoppy is standing. Both Dino and Fred are scared thinking the mouse has grown big. But Fred sees that it is Barney s pet. Fred does not like this "hopparoo" at all since it can beat him. But at a family s picnic, both pets Dino and Hoppy unexpectedly saves them from a close cliff fall...