The Cat Sidhe

The cat sidhe (Irish) or cat sith (Scottish) is a figure in folklore/mythology of a large cat that is completely black except for a white star on the creature's breast.

They can be associated with the fae (also called "Sidhe" or "Sith") or are sometimes depicted as witches who have the ability to shift between human forms and a cat. Tales with the latter often say that the witch can only go back and forth nine times, this is where the belif that cats have nine lives comes from.

The cat sidhe appears more often in Scottish folklore.