Leprechauns or "wee folk" are probably the best known of the fairy folk that inhabit Ireland. But where did they come from?
As a cousin of the far darring and the clurichaun, (drunken creatures who love to cause chaos around Ireland at night time), some say that leprechauns inhabited Ireland well before the arrival of the Celtic People.
The name leprechaun may have derived from the Irish leath bhrogan (shoemaker), which is the trade of the leprechaun. However, its origins may lie in the word leipreachán, (Irish for pygmy). Although the leprechaun has been described as Ireland's national fairy, this name was originally only used in the north Leinster area. Variants include lurachmain, lurican, lurgadhan.
But as to the actual origin of leprechauns, it is hard to say. The stories of the leprechaun were passed down in oral transmission from generation to generation and with the sudden popularity of the leprechaun in other parts of the world, due to books such as T. Crofton Croker's book "Fairy Legends and Traditions of the South of Ireland". written in 1825 and continuing into the 1940's with the musical "Finian's Rainbow" the actual story of leprechuans has been melded into the lore of other fairy folk of Ireland as well as folk of Germany and other European countries.
Even their apparently earliest appearance in medieval story called "The Adventure of Fergus son of Lete" , which says that leprechauns were originally water sprites in the eighth century CE in northern Ireland, is disputed because depictions of them from other areas around Ireland at that time portray them differently. The actual first appearance of the leprechaun as we know him (for it appears there are only male leprechauns) today we know today came from the play written in 1604 by Dekker called "The Honest Whore; Part 2" where he is called "... an Irish lubrican, that spirit whom by preposterous charms..."
Then other sources claim that leprechauns are the offspring of evil spirits and bad fairies. And one legend says that the leprechaun is actually the Irish god Lugm whose father Cian was from the clan of the Tuatha De Danann.
What does seem to be true is that leprechauns in their original form are nor the cute, mischievous fairy as depicted on boxes of "Lucky Charms" but they began as sullen, ugly and could be foul mouthed. Nor did they wear green. They were originally clad in red; the specifics of his attire varied by what region the leprechaun lived in.
So it appears that there is no real consensus of the actual origin of leprechauns. So we will have to wait until Ireland Ireland opens the first National Leprechaun musem this year in Dublin to find out the real truth.