Are there any grown-up books comparable to James and the Giant Peach?

Or grown-up books comparable to Doctor Doolittle? I read both these books (actually D. Doolittle is a series, not one specific book) and LOVED them as a kid. I was wondering if there's anything as fun and clean as these books for grown-ups. I'm sick of all the , violence, and general dirty language in "adult" books. I want something clean and imaginative and fun, like what I read when I was a kid! Any suggestions would be great.