Modern depictions of fae, or fairies, often portray them as diminutive rascals. They are all identical and somewhat mischievous in temperament. I call this the Tinkerbell effect. After the lore of the Peter Pan universe seeped into the global subconscious, there could be only one type of fae.
Fortunately for lovers of variety, the real world is far more complex. There are hundreds of different types of fae, and fairy-like creatures, from cultures all over the world. One culture stands head and shoulders above the rest for their rich fairy mythology. Irish mythology speaks of the Otherworld, where the fairies dwell in a society as complex as our own.
The Fae, like people, can be mercurial. Some days they can bring you good fortune, and other days it's best to stay out of their way. The Pooka, or Púca, is no exception. This Irish goblin has been known to shape-shift, and depending on its mood, meeting one can be very good, or very bad.
He-Goat, Master of Prophecy
Some theorize that the name, Púca, comes from the Irish word, Poc, which means he-goat. That is because the Pooka can disguise itself as a goat. They technically can turn into any animal, and in some stories they even transform into a beautiful woman. Like many other shape changers, the Pooka cannot get their forms quite right. There's always an extra detail or body part, like chains on a horse, or a tail on a woman. But I guess some people are into that.
Depending on the location, the Pooka is known either as a helpful spirit, or a malicious miscreant. Wherever you find one, though, it will likely play tricks on you. There's also the fact that they can, and will, speak in animal form. Nothing creepy about that.
The Pooka has many abilities apart from its shape-shifting. They are powerful fortune-tellers. Last but not least, they have the power of both creation and destruction. So, basically a mini chaos-god.
Regardless of their disposition, you aren't likely to even know that a Pooka is approaching you. According to the myths, they most often take the form of a black stallion when first approaching someone. Their favorite targets are drunk people, farmers working late in the fields, and lost children.
Victims of a Pooka are convinced to climb onto the "horse's" back. Because trusting a talking horse is obvious and natural. The Pooka will then race off into the night with their victim hanging on for dear life. All through the night they ride, until the dawn, when the Pooka returns its victim to where it found it.
The Good and The Bad
Pooka are associated with the festival of Samhain. They are usually appeased with offerings on the 1 November, Pooka's day. Farmers could leave out a portion of their crops as the "Pooka's Share".
There are ways to ward off a Pooka's attention. Chief among these is getting into the habit of wearing spurs on your heels. Unlike a natural horse, a Pooka doesn't deal with sharp objects in its ribs well.
Other Pookas are quite helpful. There are several folk tales of Pooka doing the housework for servants and children. That is, until the grateful human offers the Pooka a gift of nice clothing as a reward. Promptly, the Pooka thanks the person and declares their departure.