I did not read this book through before I gave it to my son -- a potentially risky move on my part -- because as soon as he saw it, he wanted it. So, we read it together. My son, at the time, was three-and-a-half years old. I wasn't sure he'd "get" the book. I was wrong. He laughed like a maniac when he reached the final two pages. We read this book several more times -- that same day. And he laughed, every time.
The cover, of course, is what my son saw first. And it is quite tantalizing in a wonderfully Magritte sort of way. This is, and probably will be, the only Bob Staake book where I can refer to the artwork as "illustration", as in singular. But it works because it is a singular illustration. I refuse to give away the ending, so no details on why the illustration works.
If you are looking for a book for a toddler or preschooler this Fall/Hallowe'en season, you cannot go wrong with this one. My little boy still carries it everywhere. And HE reads it. All the time.