Medieval people seem to have fantasised a great deal about upside down worlds, presumably because their real world was so hierarchical. I first encountered these fantasies at Malvern Priory. In the 1970s you could still enter the choir stalls and lift the seats to see the misericords underneath. As a small child I particularly enjoyed the scene of rats hanging a cat. Being carved in dark wood, underneath a seat, it doesn't photograph well. It is easier to see what is going on in this nineteenth century engraving.
Of all the upside down fantasies I have encountered since, this one is my favourite. From the rabbit's lordly expression to the little snail-of-prey, it is perfectly imagined. It appears in the Pontifical of Guillaume Durand, made in the middle of the fourteenth century. Pontificals were books of services used by bishops, so this image was originally a private joke created by a scribe for the amusement of a senior clergymen.