All things Muppet-related are immediately great – that’s pretty much a fundamental law of the universe. But sometimes, a clip of Jim Henson and the gang at work surfaces that’s even more extraordinary than usual.

This camera test, filmed in a grey, English field sometime in 1979, is amazing. While the cameraman does a dummy run to check his equipment is functioning, the puppeteers improvise joyously, with Kermit trying to explain to Fozzie that he isn’t a real bear. ‘Do you hibernate?’ he asks. ‘Only with friends,’ Fozzie replies.

Later, Miss Piggy appears, apologising for hitting her on-off amphibian boyfriend, although she adds: ‘I’m not sorry I hit Miss Mousy,’ Kermit is scandalised. ‘Is that why she broke her arm?’