Hoppy debuts in the fifth season episode "Hop Happy" (1964), where Barney Rubble and Betty Rubble acquire him as a new house pet. He babysits the kids as he takes them around in his pouch. Fred Flintstone regards Hoppy as an overgrown and obnoxious nuisance until the fateful day that the Flintstones and the Rubbles go out together on a picnic. The families' lives are endangered during the picnic and Hoppy goes for help. He made an appearance in The Flintstones & WWE: Stone Age SmackDown! wearing boxing gloves and a cameo in The Flintstones in Viva Rock Vegas.
Scriptwriter Warren Foster harks back to his days with the Warner Bros cartoon unit in the scene where Fred and Dino mistake Hoppy for a giant mouse. Hoppy appeared sporadically through the end of the series and is featured in various Flintstones merchandise. Most notably, he appears in The Flintstones: The Rescue of Dino & Hoppy, a video game for Nintendo, made by Taito. A CG animated hopparoo makes a small appearance in the second live-action film The Flintstones in Viva Rock Vegas and while not meant to be Hoppy it was a clear reference to the character.