Mo Willems burst on the picture book scene in 2003 with Don't Let the Pigeon Drive the Bus! (Hyperion). People stood up and took notice of the plucky—OK, pushy—Pigeon. So did the Caldecott committee, which awarded the book a 2004 Caldecott Honor. Four more titles about Pigeon have followed, and Willems now has a total of 13 books for children under his belt.

Fans of the Pigeon books may have noticed a cinematic quality to the tales, and that's no coincidence. Willems spent nine years as a writer and animator for Sesame Street, picking up six Emmys along the way. All of which turned into the perfect preparation for a children's book career, he realizes. "I had some art background, did some writing, storyboarding and stand-up comedy. Had I planned it, it would have been the perfect trajectory." And he says he doesn't miss the world of television a bit. "The schedules are insane. Books are fun to make: I get to draw, experiment—it's liberating. I like the physicality of the books better."

Though his picture books may be shorter than a TV segment, they are still full-fleshed stories. "I want my characters to have full emotional lives," he says. "They need to go through trials and tribulations. My ultimate goal is to get kids to make up their own stories."

This spring Willems debuts a line of easy readers, starring best friends Elephant and Piggie. "I just love those guys," he says. "Their relationship is so adorably flawed and perfectly real. It's really fun to spend time with them and draw them. And unlike Pigeon, they're not as demanding of me."