Tra la laaa, laaa la la laaaaa, One banana two banana three banana four....... etc.
I was actually quite scared of the Banana Splits. Especially Bingo, the gorilla with big teeth. (*shudder).
The other three were Fleegle-a beagle, Snorky-an elephant and Drooper-a lion.
Basically, they ran around doing slapsticky things, and showed cartoons like Arabian Knights.
Interestingly, Bingo was voiced by Daws Butler who also did Dick Dastardly, Fleegle was voiced by Paul Winchell who did Tigger, Snorky was Don Meswick who did Mutley and Allan Melvin did Bluto from Popeye.