In the film Madagascar 3, Alex thus upbraids Marty, a zebra, for driving a van: “What are you doing? Zebras can’t drive. Only penguins and people can drive!”

It reminds me of one of the craziest jokes I’ve ever heard, an emblematic example of the fantasy scenarios that many jokes have – you know, the “a horse goes into a bar” situation.

Anyhow, a penguin is driving through the desert (as they do – i.e. drive cars and go through the desert). The car engine begins to sound dodgy and the penguin is happy when he realises he is approaching a town; happier still when he sees a garage. He pulls in and asks the mechanic if he’d mind taking a look under the bonnet to check all is OK. While this is being done, it being exceedingly hot, the penguin takes himself off to an ice-cream parlour and orders a tub of vanilla ice cream. Of course, since he’s a penguin he has flippers rather than fingers, and eating ice cream – much as it’s refreshing – is a messy affair. By the time he gets back to the garage, his bill is covered in the stuff. He arrives just as the mechanic is coming out from under the bonnet. He looks at the penguin and explains: “Looks like you’ve just blown a seal.” Horrified, the penguin wipes his mouth and face and stammers: “No, this is ice cream…”