This book, by Arnold Lobel, was one of my favourites as a child. I had completely forgotten about it until I came across it in a church we were visiting in Dorset (in the kiddie corner). It is, as I recall - I left the book in the church you will be glad to know!) a about a very naughty prince who is naughty to the wrong person - a witch - who turns him into a dragon. Fortunately (for PB) he manages to redeem himself and be turned back into a boy/prince.
Anyway, it seems wrong for it to be forgotten...does anyone else remember it?