Cat-sìth
The cat-sìth (, plural cait-shìth), in Irish cat sí () is a fairy creature from Celtic mythology, said to resemble a large black cat with a white spot on its chest. Legend has it that the spectral cat haunts the Scottish Highlands. The legends surrounding this creature are more common in Scottish folklore, but a few occur in Irish. Some common folklore suggested that the "cat-sìth" was not a fairy, but a witch that could transform into a cat nine times. The cat-sìth may have been inspired by the Scottish wildcat itself. It is possible that  the legends of the "cat-sìth" were inspired by Kellas cats, which are a distinctive hybrid between Scottish wildcats and domestic cats found only in Scotland (the Scottish wildcat is a population of the European wildcat, which is absent from elsewhere in the British Isles). Appearance. The "cat-sìth" is all black with the exception of a white spot on its chest. It is described as being as large as a dog and chooses to display itself with its back arched and bristles erect. The King of the Cats. In the British folk tale "The King of the Cats", a  man comes home to tell his wife and cat, Old Tom, that he saw nine black cats with white spots on their chests carrying a coffin with a crown on it and one of the cats tells the man to "Tell Tom Tildrum that Tim Toldrum is dead." The cat then exclaims, "What?! Old Tim dead! Then I'm the King o' the Cats!" Old Tom then climbs up the chimney and is never seen again. Soul-stealing. The people of the Scottish Highlands did not trust the "cat-sìth". They believed that it could steal a person's soul , before it was claimed by the gods, by passing over a corpse before burial; therefore, watches called the "Fèill Fhadalach" (Late Wake) were performed night and day to keep the "cat-sìth" away from a corpse before burial. Methods of "distraction" such as games of leaping and wrestling, catnip, riddles and music would be employed to keep the "cat-sìth" away from the room in which the corpse lay. In addition, there were no fires where the body lay, as it was said that the "cat-sìth" was attracted to the warmth. Samhain. On Samhain, it was believed that a  cat-sìth would bless any house that left a saucer of milk out for it to drink and those houses that did not put out a saucer of milk would be cursed into having all of their cows' udders go dry. Summoning. The demonic "cat-sith" called Big Ears could be summoned (Gaelic "taghairm" ) to appear and grant any wish to those who took part in the ceremony. The ceremony required practitioners to burn the bodies of cats over the course of four days and nights. Transformation. Some people believed that the "cat-sìth" was a witch that could transform  voluntarily into its cat form and back nine times. If one of these witches chose to go back into their cat form for the ninth time, they would remain a cat for the rest of their lives. It is believed by some that this is how the idea of a cat having nine lives originated.