Since college, I have been slowly collecting all the Caldecott (and Newberry) award winners (and some of the honor books). I bought this one, The Lion and The Mouse, (the 2010 winner) a few years ago.
It is a wordless, illustrated book retelling one of Aesop's fables. I was reluctant to add it to Theo's library since it is so gorgeous, and I haven't actually spent a lot of time with this book yet with Theo, but someone has, because this was what happened during playtime today.
Theo (to Eli):
"You mouse. I a lion. ROAAAARRRRRR!
Don't wake me up!"
It was too cute for words.