Hey all. This post isn't about a work of fiction I've created or anything, it's just about books.
I've recently started the Animorphs series of books, which I'm sure many of you are familiar with. However, I've found that these books are targeted at the audience of kids around middle school or high school age. They're a bit simple and predictable for me now. But I really like the morphing aspect, and how they solve problems by turning into animals. Really cool stuff, to me.
I was wondering if any of you know about books (or series) that are similar to Animorphs, but not so kiddie. And please don't suggest Twilight because it has werewolves.

Awesome!