From the now sadly defunct “Stickers on the Central Line” Tumblr, are these hilarious and superbly executed “prank” stickers found on the London Underground. Matching the original strip map almost exactly, they instead insert something unexpected, pointed, or just plain funny.

My favourite? Change at Tottenham Court Road for a submarine to Somalia, complete with a very plausible London Underground submarine icon.

More here in this imgur album. Hat tip to Twitter user Ben Darfler.