Shape-Shifter: The Naming of Pangur Ban — Fay Sampson

Deep in a mountain cave a witch is plotting mischief: "We need something small, something sly, to carry a spell . . . and then we shall see who reigns on the Black Mountain!" The kitten Shape-Shifter is her victim. But before the charm is complete, the kitten escapes. He flees, in a terrifying chase, caught in a spell gone wrong and a shape that he cannot control. He brings disaster even to those who want to help him. Is there another power that can break the spell?