The Leprechauns are creatures of Irish folklore, usually taking the form of an old man, clad in a red or green coat, who enjoys partaking in mischief. Their principal occupation is making and mending shoes. They were thought to own treasures, deriving from "treasure-crocks, buried of old in war-time", which they have uncovered and appropriated.
Like the older Tuatha de Danaan, they were connected to ancient tombs of the dead. There are theories that various mythical creatures of Celtic (including Irish) folklore derive from the ancient practice of worshipping the spirits of your ancestors.