The World Turtle is a gigantic turtle on the shell of which stand four massive elephants, which, in turn, hold up the mass of The Disk. Every few thousand years the turtle meets with another turtle in space and mates with it, in what has become known as a Great Mating. Nobody knows what the turtle eats, or even how it knows where to swim in the vast emptiness of space. All that is known for sure is that it seems to be going somewhere, and that everyone is coming along for the ride.