A Field Guide to Irish Fairies

It is not, of course, an exhaustive guide, and deliberately so, because I am reminded of a warning given to the Irish poet W. B. Yeats by the Queen of Fairies, through a Dublin medium. [...] "Be careful, and do not seek to know too much about us!"

One of the best known supernatural figures in Ireland is the banshee, the restless spirit which follows those Irish families with pure Celtic blood in their veins and warns them of death with her wailing keen.

Fairies can be willful and capricious creatures, easily offended and quick to anger. They are often spiteful and jealous of mankind, which enjoys a special relationship with God which they cannot. Nevertheless, they can also be good-hearted and merry and many accounts assert the beauty of their music and their love of sport and revelry.

She [the banshee] has also appeared in a variety of other forms, such as that of a hooded crow, stoat, hare and weasel. All these animals are associated with witchcraft and give the banshee a sinister magical aspect.

The sheerie is one of the most unusual and potentially the most dangerous of all Irish fairies. Sheerie [...] are strange, phosphorescent creatures who combine elements of both human and fairy nature. [...]
They are believed to be the souls of unbaptised children (probably those who died at birth) trying to return to the mortal world.

In some counties [the Sheerie] are considered to be infallible harbingers of ill omen, their very presence portending ill luck and even death to anyone who sees them. Their source of amusement is, by sorcery, to lead astray those who venture out after dark and cause them to wander aimlessly all over the countryside until the sheerie choose to release them from the spell.

Being a creature of mist and fog, the Grey Man sustains himself on the smoke from the chimneys of houses. For this reason, he is one of the few fairies that will venture close to large towns or cities, where he can be just as troublesome as in the country or the scattered communities along the seashore. […]
The Grey Man delights in the loss of human life and may use his misty cloak to deadly effect.

Of all the Irish fairies, the grogoch is perhaps the most sociable towards humans.

Many coastal dwellers have taken merrows as lovers and a number of famous Irish families claim their descent from such unions, notably the O'Flaherty and O'Sullivan families of Kerry and the MacNamaras of Clare. The Irish poet W.B.Yeats reported a further case in his "Irish Fairy and Folk Tales" : "Near Bantry in the last century, there is said to have been a woman, covered in scales like a fish, who was descended from such a marriage."

No luck will come to a family in which there is a changeling because the creature drains away all the good fortune which would normally attend the household. Thus, those who are cursed with it tend to be very poor and struggle desperately to maintain the ravenous monster in their midst.