Tailchaser's Song by Tad Williams
Mass market paperback format. Highly recommended!
Fifteen years ago, a young author surprised and enchanted readers with his first novel—the story of Fritti Tailchaser, a courageous tom cat in a world of whiskery heroes and villains, of feline gods and strange, furless creatures called M'an.
The book was Tailchaser's Song, the author was Tad Williams.The legend was born.