The pooka are shapeshifting Celtic faeries known for their mercurial nature and ability to bring both weal and woe.  Pookas can take a number of different forms, but the most popular are that of a horse, cat, rabbit, raven, fox, wolf, goat, goblin, or dog.

A pooka will often appear in one of its many animal forms, but as a shapeshifter it can just as easily appear as a human.  However, it's said that the pooka are so fond of their animalistic nature that they will often exhibit one or more animal traits, even when walking as a man.  The pooka are known to possess the power of human speech as well, and will often wait outside of a person's home and call their name before stealing them away for a wild midnight ride.  

One of the most iconic shapes taken by the pooka is that of a horse, like the one ridden by Brian Boruma Mac Cennetig (941-1014), the High King of Ireland and founder of the O’Brien dynasty.  He is said to be the only man to ever successfully ride a pooka. According to legend, the king controlled the creature by using a special bridle containing three hairs from the pooka’s tail. King Brian’s physical prowess allowed him to ride the pooka into exhaustion until it finally surrendered to him.

Púca, the old Irish name for pooka, is the word from which the mischievous satyr Puck derives his name. Puck, or Robin Goodfellow, is known for his animalistic appearance, complete with a goat’s horns and legs.  In a fashion similar to that forest faerie, a pooka in County Roscommon, Ireland, is said to appear as a large, black goat with curling horns and gleaming red eyes.  Many people believe that the legends surrounding Puck at least partially arose out of the stories told of pooka in their goat form.

These capricious faeries are known to be very dangerous, but a particularly clever person is said to be able to occasionally trick them into service.  In this endeavor it is best to be ready to flee after gaining whatever favor you're after from the pooka, unless, of course, you have a magic bridle--and even that probably only works if you're a king.  In any case, never leave your house to investigate a stranger lurking outside calling your name, especially if they happen to be standing on a pair of goat legs, or you just might find yourself on a very unpleasant nighttime ride with the pooka.