I'm a big fan of Mo Willems. You may have already guessed that from my review of Knuffle Bunny.
Mo started out as an animator for Sesame Street. I watch a LOT of Sesame Street (well, my son does, and I watch it with him) and I've had many guesses about what Mo animated, but it's nice to have some actual titles and images to go along with my suspicions. Thanks to this mention by Fuse #8, I was able to find three examples of his early work on Youtube.
Check them out:
A spokesman talks about the letter L
I have a small octopus on my head
I loved watching these because they're so different, and yet so similar to his later work.
Check out Mo's blog.... he has a brief mention of the videos and a sneak peek at one of his upcoming books. I love seeing sketch by sketch versions of final images.