In Terry Pratchett's Discworld novels, Great A'Tuin is the giant turtle who travels through space and which carries the four giant elephants who in turn carry the Discworld. The turtle's sex is unknown, and this vital piece of information is currently under investigation by some of the disc's finest scientific minds. The sex of The World Turtle is pivitol in proving or disproving a number of conflicting theories about the destination of "Great A'Tuin's" journey through the cosmos. If (as one popular theory states) "Great A'Tuin" is moving to his(or her) mating grounds at the point of mating will the civilisations of the disc be crushed or simply slide off, obviously this is a vital piece of information for the people of the disc. The idea of a turtle-carrying-elephant-carrying world is Indo-European; see for instance The King and I and Brewer's Dictionary of Phrase and Fable.