A leprechaun is a diminutive supernatural being in Irish folklore, classed by some as a type of solitary fairy. They are usually depicted as little bearded men, wearing a coat and hat, who partake in mischief. In later times, they have been depicted as shoe-makers who have a hidden pot of gold at the end of the rainbow.

The earliest known reference to the leprechaun appears in the medieval tale known as the "Echtra Fergus mac Léti" (Adventure of Fergus son of Léti). The text contains an episode in which Fergus mac Léti, King of Ulster, falls asleep on the beach and wakes to find himself being dragged into the sea by three lúchorpáin. He captures his abductors, who grant him three wishes in exchange for release.

The leprechaun has become one of the most beloved and popular good luck symbols associated with Ireland.

These little green men are mostly harmless to humans. They can from time to time be mischievous and practical jokers.

Leprechauns are not social creatures and quite difficult to find. They live in remote areas and underground.

They are very short and will be able to fit through small openings in the ground and in caves which humans cannot possibly enter.

It is easier to hear a leprechaun than to see one.

More Info: en.wikipedia.org