Although the animated stone-age satire The Flintstones began its fifth season in the same early-Thursday-evening timeslot that it had occupied during Season Four, the fierce competition from rival series The Munsters forced ABC to shuffle The Flintstones to Friday nights, switching slots with another Hanna-Barbera prime time effort Jonny Quest during Christmas week of 1964. The season began with "Hop Happy", which introduced a new addition to the home of Fred and Wilma Flintstone's neighbors Barney and Betty Rubble, a pet "hopperoo" (a cross between a dinosaur and a kangaroo, natch!) Eight episodes later, the grotesque Gruesome family moved into Fred's neighborhood; although some have suggested that the Gruesomes were inspired by the like vintage sitcom The Addams Family, they were in fact derived from an equally repulsive cartoon family, Mr. and Mrs. J. Evil Scientist and their son Junior, who'd been seen in several of Hanna-Barbera's "Quick Draw McGraw" cartoon shorts. Highlights this season include "Dr. Sinister", a wild-and-wooly takeoff of the James Bond movies; "Time Machine", in which the Flintstones and the Rubbles are thrust into the "future", namely 1964; "Monster Fred", which finds Fred, Barney, Wilma and Betty exchanging personalities over and over again; "Fred Meets Hercurock", a spoof of sword-and-sandal epics featuring a Joe Levine-type fast buck movie producer named "Go Go Ravine"; "The Rolls Rock Caper", in which a millionaire cop named Amos Boulder amusingly sends up the TV detective series Burke's Law; and "Christmas Flintstone", the first of the property's several Yuletide offerings -- all of which blithely ignored the fact that Flintstones were supposed to be living in the B.C. era! The last-named "Christmas Flintstone" yielded yet another of the series' many musical highlights, in this case a soon-to-be-popular children's tune called "Dino the Dinosaur". Better still is "Surfin' Craze", performed by singer James Darren (aka "James Darrock) in another fourth-season offering, "Surfin' Fred."