Crookedstar's Promise

Crookedstar's Promise, is a great book, about a kit called (first of all) Stormkit, who is disfigured for life when a tragedy befalls him. His mother, Rainflower, casts him aside and re-names him Crookedkit. As he struggles to prove to his clan-mates that he is ready to become an apprentice, he makes a seemingly harmless promise. That promise, however, turns out to be much more disastrous than he ever could have thought...

I recommend this book for readers aged 9-12.