This was a book about a caterpillar who was very hungry (no, not that book), who every time he found something delicious to eat discovered that all was not as it seemed. Basically, as you read the book, you turned it to follow the writing until the book was upside down and the picture suddenly became something completey different. For example: two ice creams in cones when turned upside down became clowns with frilly necks. It was a very clever book and I loved it as a child. Hoping to get hold of a copy for my own children.