It featured the adventures of a musical quartet, meant to be reminiscent of the Beatles and the Monkees, consisting of Fleegle, a beagle; Bingo, a gorilla; Drooper, a lion; and Snorky, an elephant. The characters were played by actors in fleecy costumes: the voices were provided by such notable voice actors as Paul Winchell and Daws Butler. They lived in Hocus Pocus Park, where the cuckoo clock always read 6:55. "Tra-la-la Song" was their theme.
Fleegle was the only character that did not wear glasses.
The cartoon segments included The Arabian Knights, The Three Musketeers, The Hillbilly Bears, and Micro Venture.
In a live action segment of the show known as Danger Island, a young Jan-Michael Vincent played Lincoln 'Link' Simmons.
The series was created by Hanna-Barbera and Sid and Marty Krofft.