One of my favorite childhood books of all time, and one of the first books I remember enjoying, was The Monster At The End Of This Book.
A Little Golden Book featuring Sesame Street‘s Grover, TMATEOTB is a “post-modern” book in which Grover breaks the fourth wall, pleading with readers not to turn the pages so that they won’t meet the monster he has read about in the title. Along the way, he tries to fix pages so that the reader can’t turn them, nailing some and bricking up others. These plans are repeatedly foiled as the reader turns the page, and the destruction of these plans can be found on the subsequent pages (fallen bricks, busted wood planks, etc). When we get to the end, we discover that the monster at the end of the book is (SPOILER!) Grover himself, a joke that delighted me as a kid and still delights me today.
Recently I was able to share this experience with my 2-year-old daughter via an Amazon app called Another Monster At The End Of This Book. This app features Elmo and Grover in an updated, interactive remake of the original. My daughter loved it, and I thought it was okay, but, as with most remakes, I prefer the original.