Children's book, rabbit who learns to shapeshift

[Arliss]

I'm looking for a fantasy children's chapter book. It involved a young rabbit who goes on a quest, makes various friends (I recall a young/teenage human girl and a large human man?) and meets a sorceress who teaches him to shapeshift--somebody shapeshifts into a snake at some point. I read it around '97-'99 but I unfortunately don't know when it was written.

Thank you in advance for your help! 🐇

[Rainbowheart]

Perloo the Bold?

[Arliss]

Rainbowheart wrote: "Perloo the Bold?"

It wasn't an Avi book, unfortunately. Thanks anyway, though!