Animorphs Book 23: The Pretender by K. A. Applegate

Tobias tries to decide how to be himself & whether that means being human, hawk, or a strange mix of both. The Tobias/Rachel storyline is developing in a really cool way, w/some things said explicitly instead of heavily implied.

The layers of deception and pretense are very thick. The titles usually work on several levels, but wow, this one does a lot. There are tricks, traps, pseudonyms, several kinds of impostor syndrome...