Synopsis by Hal Erickson
Barney and Betty Rubble acquire a new house pet as The Flintstones launches its fifth season. The pet in question is Hopparoo, sort of a combination kangaroo and dinosaur. Grumpy Fred regards "Hoppy" as an overgrown and obnoxious nuisance until the fateful day that the Flintstones and the Rubbles go out together on a picnic. Scriptwriter Warren Foster harks back to his days with the Warner Bros. cartoon unit in the scene where Fred and Barney mistake "Hoppy" for a giant mouse. And incidentally, this episode marks the "official" Flintstones debut of Gerry Johnson as the voice of Betty Rubble, taking over from Bea Benaderet.