Dictionary.com defines "meta" as: "pertaining to or noting a story, conversation, character, etc., that consciously references or comments upon its own subject or features, often in the form of parody."

See also: breaking the fourth wall -- in other words, when something such as a play, movie, or book acts as if conscious of its status as a play, movie, or book, by means of referencing the audience, alluding to itself as fictional, etc. Here are some picture books that, in one way or another, seem conscious of their audience, or of themselves as books.

While I'm generally not a fan of picture books based on TV characters, The Monster at the End of This Book is a clear exception. Since it's been around for 45 years now, this is probably one of the more obvious meta picture books for people from my generation. Grover is quite emphatic throughout the book that the reader must not turn any more pages, because that will only get them closer to the monster at the end of the book, and he devises all kinds of ways to make them/us stop. Even though I didn't grow up with this book, I've really enjoyed it, and my children have too -- especially once they realized it wasn't as scary as it sounded.

A Book, by Mordicai Gerstein, is almost entirely meta, because the characters know they live in a book, and the main character is a girl in search of her story. She lives with family members who go off to their "character jobs" in the morning, while she has to find out what hers is, searching through pages of fairy tale characters, mysterious characters, pirates, and even a historical novel. By the end, she finds a way to take ownership of her distinct story. I thought this book was pretty clever, and I like how the scenes are drawn at something of an angle, with shadows that make it feel as though you're looking down into a three-dimensional world rather than the flat pages of a typical book.

All of us here enjoy the "Elephant & Piggie" series by Mo Willems, but We Are in a Book! is definitely my favorite. These books are written in "graphic novel" style, with colored speech bubbles to make it easier for young readers to see who is talking, though these can be enjoyed by pre-readers as well. In this book, Gerald (the elephant) and Piggie become aware that they are being read by a reader. This is very exciting to them -- until Piggie informs Gerald that the book is eventually going to end, which causes a bit of a freak-out. 

The Hole, by Norwegian artist Oyvind Torseter, was an interesting library find for us -- the book simply has a hole punched all the way through it, and the mostly wordless story involves someone moving into his new apartment and encountering "the hole," which moves about until he is finally able to capture it for analysis. Though of course, since the hole goes right through the book, it can never really go away...

The Red Book, by Barbara Lehman, is a short, wordless story about a boy who finds a magic book, which functions something like a mirror that allows him to make a connection with someone far away.