Pooka

"The púca (Irish for spirit/ghost; plural púcaí), pooka, phouka, phooka, phooca, puca or púka is primarily a creature of Celtic folklore. Considered to be bringers both of good and bad fortune, they could either help or hinder rural and marine communities. Púcaí can have dark or white fur or hair. The creatures were said to be shape changers which could take the appearance of horses, goats, cats, dogs, and hares. They may also take a human form, which includes various animal features, such as ears or a tail." —Wikipedia