The Banana Splits
Mod rockers Fleegle (dog, guitar), Bingo (gorilla, drums), Drooper (lion, guitar) and Snorky (elephant, organ) hosted their own Saturday morning kids show, The Banana Splits Adventure Hour (1968-1970). I mainly remember them introducing cartoons, running into each other, and driving kick ass six-wheeled dune buggies, but I guess they must have played some songs or something, because they managed to put out an album. They have a second life now as a Cartoon Network web cartoon!
Trivia Time! While the characters were invented by NBC, but they went to the Krofft brothers to design the costumes.