The púca (Irish for goblin), pooka, ""phooka"", phouka, phooca or púka is a primarily a creature of Irish folklore. Considered to be both bringers of good and bad fortune, they could either help or hinder rural and marine communities. The creatures were said to be shape changers which could take the appearance of black horses, goats and rabbits.
The púca has counterparts throughout the Celtic cultures of Northwest Europe. For instance in Welsh mythology it is named the pwca or pwwka and in Cornish the Bucca. In the Channel Islands, the pouque were said to fairies who lived near ancient stones; in Guernésiais and Jèrriais a cromlech is referred to as a pouquelée or pouquelay(e), poulpiquet/polpegan are corresponding terms in Britany.
Malevolent or benevolent nature 
The pooka may be regarded as being either menacing or beneficent. Fairy mythologist Thomas Keightley said "notions respecting it are very vague," and in a brief description gives an account collected by Croker from a boy living near Killarney that "old people used to say that the Pookas were very numerous...long ago..., were wicked-minded, black-looking, bad things...that would come in the form of wild colts, with chains hanging about them." and that did much to harm unwary travelers. Also, children were warned not to eat overripe blackberries, because this was a sign that the pooka has befouled them.
In contrast, the phouka is represented as being helpful to farmers by Lady Wilde, who relates the following tale. A farmer's son named Phadraig one day noticed the invisible presence of the phouka brushing by, and called out to him, offering a coat. The phouka appeared in the guise of a young bull, and told him to come to the old mill at night. From that time onward, the phoukas came secretly at night and performed all the work of milling the sacks of corn into flour. Phadraig fell asleep the first time, but later concealed himself in a chest to catch sight of them, and later made a present of a fine silk suit. This unexpectedly caused the phoukas to go off to "see a little of the world" and cease their work. But by then the farmer's wealth allowed him to retire and give his son an education. Later, at Phadraic's wedding, the phouka left a gift of a golden cup filled with drink that evidently ensured their happiness.
Morphology and physiology 
According to legend, the púca is a deft shapeshifter, capable of assuming a variety of terrifying or pleasing forms, and may appear as a horse, rabbit, goat, goblin, or dog. No matter what shape the púca takes, its fur is almost always dark. It most commonly takes the form of a sleek black horse with a flowing mane and luminescent golden eyes. (The Manx glashtyn also takes on human form, but he usually betrays his horse's ears and is analogous to the each uisce)
If a human is enticed onto a púca's back, it has been known to give them a wild ride; however, unlike a kelpie, which will take its rider and dive into the nearest stream or lake to drown and devour him/her, the púca will do its rider no real harm. However according to some folklorists the only man ever to ride the púca was Brian Boru, High King of Ireland, by using a special bridle incorporating three hairs of the púca's tail. The púca has the power of human speech, and has been known to give advice and lead people away from harm. Though the púca enjoys confusing and often terrifying humans, it is considered to be benevolent.
Agricultural traditions 
Certain agricultural traditions surround the púca. It is a creature associated with Samhain, a Goidelic harvest festival, when the last of the crops are brought in. Anything remaining in the fields is considered "puka", or fairy-blasted, and hence inedible. In some locales, reapers leave a small share of the crop, the "púca's share", to placate the hungry creature. Nonetheless, November 1 is the púca's day, and the one day of the year when it can be expected to behave civilly.
At the beginning of November, the púca was known—in some locales—to either defecate or to spit on the wild fruits rendering them inedible and unsafe thenceforth.
Regional variations 
In some regions, the púca is spoken of with considerably more respect than fear; if treated with due deference, it may actually be beneficial to those who encounter it. The púca is a creature of the mountains and hills, and in those regions there are stories of it appearing on November Day and providing prophecies and warnings to those who consult it.
In some parts of County Down, the púca is manifested as a short, disfigured goblin who demands a share of the harvest; in County Laois, it appears as a monstrous bogeyman, while in Waterford and Wexford the púca appears as an eagle with a huge wingspan and in Roscommon as a black goat.
See also 
- Koch, John T.: Encyclopedia of Celtic Culture, page 729. ABC-Clio, 2006
- Mackillop 1998, under pooka
- Thomas Price (Carnhuanawc) (1830), "A Tour through Brittany" (google), Cambrian quarterly magazine and Celtic repertory 2: 23–43, p.23–24 "These cromlechs, or kistvaens,.. are called in Jersey poquelays, and in Brittany policans & poulpiquets, &c."
- Loth, J. (1894), "le Nain de Kerhuiton" (google), Annales de Bretagne 10: 78–
- Curran, Bob (1997). A Field Guide to Irish Fairies. Appletree Press. ISBN 0-86281-634-3.
- Keightley 1880, Fairy Mythology, p.371
- Wilde 1887, Ancient Tales, p.48
- The contrast between Croker's and Wilde's notions are taken from Mackillop 1998 under "pooka", except mention could not be found in Croker's body of works as Mackillop states, but only via Keightley.
- Yeats, W.B.: "Fairy and Folk Tales of the Irish Peasantry", in A Treasury of Irish Myth, Legend, and Folklore, p 94, ISBN 0-517-48904-X.
- Mackillop 1998, under glashtin
- Ó hÓgáin, Dáithí: The Lore of Ireland, page 270. The Boydell Press, 2006.
- Katharine Briggs, An Encyclopedia of Fairies, Hobgoblins, Brownies, Boogies, and Other Supernatural Creatures, "Pwca", p 337. ISBN 0-394-73467-X.
- Mackillop, James (1998), Dictionary of Celtic Mytholgy, Oxford: Oxford University Press, ISBN 0-19-280120-1
- Keightley, Thomas (1880), The Fairy Mythology (google), p. 371
- "Chapter: Fairy Help (The Phouka)", Wilde, Jane Francesca Elgee (Lady) (1887), Ancient legends,mystic charms,and superstitions of Ireland (google), p. 48 (Boston, Ticknor, 1888)