Knock, knock. Who’s there? It’s a new companion book to David Ezra Stein’s 2011 Caldecott Honor title Interrupting Chicken—and we have the first look at the cover. Candlewick will be publishing Interrupting Chicken and the Elephant of Surprise on September 11.

Stein dreamed up the impatient and exuberant young star of Interrupting Chicken when he thought back to a favorite knock-knock joke from his childhood. But before the little red chicken ever landed on the page, Stein had been kicking around some ideas for another, much larger, animal. “I had had the idea of the ‘elephant of surprise’ for a while, as a separate character,” he said. “My idea was to have scenes of stuffy people talking about something boring, and then suddenly this elephant would just burst in and knock over the furniture or the tea set. I did some development, but it wasn’t quite coming together as a full-fledged book, so I put it aside for awhile.”

But in the last couple of years, in the wake of Interrupting Chicken’s popularity—and especially seeing kids’ enthusiasm for it whenever he did appearances—Stein knew he wanted to do another book with those same characters. Then he had a bit of a brainstorm: “What if I put that elephant in the chicken’s world?” Similar to the way he based the chicken on a joke, Stein noted that the elephant “is based on a pun, or wordplay, and is a goofy jack-in-the-box character that can be a lot of fun. When I tried putting him into the chicken’s world of reading stories with her father, it suddenly came into place; it seemed he was a natural.”

Stein explained how sticking with different characters and scenarios is part of his creative process. “I never give up on ideas,” he said. “I have many of them on the back burner, and many journals filled with images and bits of stories. I may not live long enough to do all of them, but it’s a very satisfying thing when one of them falls into place and becomes a book.”

In the new book, the chicken comes home from school excited that she’s learned about “the elephant of surprise.” Her father inquires, “Don’t you mean the element of surprise?” He then goes on to explain that the element of surprise is “the part of the story that makes you say, ‘whoa! I didn’t know that was going to happen.’ ” To which the young chicken responds, “Well, an elephant in a story always makes me say ‘whoa!’ ” As part of young chicken’s “homework,” she and Papa read three familiar fairy tales together, in which the elephant makes unexpected and absurd appearances.

For the cover image, Stein wanted to include the familiar father-daughter chicken duo and introduce the elephant in the room, too. “It was a bit of a design challenge to get all the characters in there,” he admitted. “I wanted the elephant to be tempting you to come into the book by being cute and showing you that he really is there and you have to look for him.” He noted that within the story, “it’s almost like hide-and-seek between the chicken and elephant, so it’s got that tantalizing ‘come and find me’ thing going on on the cover.”

Stein is eager to see the reaction to Elephant of Surprise from fans of Interrupting Chicken. But he’s also excited about another companion project he has on tap. Honey, a follow-up to his book 2007 title Leaves, comes out from Nancy Paulsen Books on March 27. “I’m really proud of that one too,” he said. “It’s like a new visit with an old friend from the beginning of my career, and Bear is one of my favorite characters.”

Stein feels a fondness for both the chicken and the bear, believing that those two characters are the “closest to who I am. They’re very different from each other. One is a lot more meditative and reflective and the other is much more bouncy and impatient.” He recalls that his cousin and dear friend once said, “ ‘I think your best books are the ones that are the most you,’ and I thought, yeah, that’s true. Isn’t that cool how the most truthful thing becomes the most accepted by other people? I feel like that’s how I want things to be—that if something is important to me it will be important to someone else.”

In addition to working on other potential book projects, Stein is also developing a puppet show based on Interrupting Chicken with his wife (prior to his publishing career, Stein held an early job in the Swedish Cottage Marionette Theatre in New York City’s Central Park.) “We’re both really into puppetry,” he said, “and it’s something that I love to do—bring a live show to kids.” The couple hopes that the eventual production is something they’ll be able to take around to schools. “It’s magic,” he said. “There’s just something about it, even for adults. When you see a puppet, there is that sense of wonder.”