(zippy and george are puppets, bungle is a man in a bear suit and geoffrey is their human friend)
The sketch opens with Zippy peeling a banana...
Zippy: "One skin, two skin, three skin, four"
George: "Zippy, where is Bungle?"
Zippy: "I think Geoffrey is trying to get him up"
If it's all a fake then they did a good job of it.