An ancient prophecy announced that one day, upon the arrival of a decisive event (the nature of the event varies wildly from one telling to another), people would be able to see flying pigs playing polo with the stars. While this version of the actual prophecy is outrageously deformed, the Star-Sporting-Pigs it depicts are true; actually, the story of a prophecy was entirely made up by the minds that observed those creatures to bring some sense and dignity back to the universe. They failed, but that is not the point.