The book begins with a poorly rhymed limerick, changes to prose, and then goes back to limericks. This continues throughout the book, the rhyming becoming more and more clumsy. I can’t imagine a child trying to follow the narration.
William imagined himself as a variety of creatures that would, hopefully, be better liked by humans, such as elephant, giraffe, shark, and snake. Each incarnation comes with its own set of problems. Unfortunately this goes on far too long. In the end he decides to be himself.
This theme has been done dozens of times in better ways. Perhaps the author was trying to do it in an original way with the limericks, but it just doesn’t work.