The Guinea Worm is a type of parasitic worm that has developed a taste for human flesh (and dogs, but it's just us two). It starts life as a little larva contained in a flea that is swimming around in drinking water. When humans drink that water, its protective flea-ship is dissolved by the stomach acid and the larva finds a nice little nook to burrow its way into. It doesn't stay little for long, however, as it grows and grows to about three feet long. It's about at this point that it decides to go for a little wander around, burrowing up to the surface of the skin where it creates a little sore which is usually the first sign someone has that they're got one of these critters cruising around their system You'd think that a parasite that can feed off its host undetected would want to stay that way, but the problem is that they don't want to have to share that space with their foul offspring. It just so happens that the irritation caused by the worm will cause most hosts to go and dunk the affected area in some water as this offers relief. This is exactly what the worm wants as it will then poke its head out and vomit up some little larvae of its own which will float around the drinking water and begin the whole process again. Ahh, the circle of life... The best way to get rid of this freeloader is to grab its head as it pokes out and wind it round a goddamn stick. If the worm ends up dying inside you then it can get jammed up in joints and cause arthritis. One has even been found calcified inside an Egyptian mummy. Now, excuse me whilst I go scratch my skin off.