The credits are set to the tune of "Always Look on the Bright Side of Life", sung by Eric Idle in the film Life of Brian (1979). It starts out with a family of Australopithecus listening to the music, and continues with various animals featured in the program performing circus acts: monkeys and a brontothere do high-wire stunts, a mammoth rolls on top of a ball, and an Australopithecus sticks his head into a saber-tooth cat's mouth. All the while, the Australopithecus family walks off into the savanna, snapping their fingers to the tune of the song.