Rats and other vermin live in the London Underground, and there are probably urban legends around about bigger, nastier animals down in the Tube. But a whale? An elephant? And an emu? How about a penguin, a polar bear and a baby rhino? All these and more species, enough to fill a zoo, live in the Underground – but not in the actual tunnels: they’re cleverly hiding in the map of the Underground.

Have a look at this site (which I found via this collection of cartographic curiosa) and check out all the beasts squatting in the Tube Map. And re-baptise familiar stations into code-named locations of this parallel-universe bestiary: Oxford Circus station is the Whale’s Eye, the station at St Paul’s is the Pig’s Smile, Stratford is the Penguin’s Arse… Hours (well, minutes) of fun guaranteed! And afterwards, you can buy the t-shirt.