Wonder who the inspiration is for Trixie, the little girl in Mo Willems' Knuffle Bunny books?

Well, duh, it's Trixie, Mr. Willems' 6-year-old daughter, who also voices Trixie in the DVD adaptations of the books.

So, did Trixie's Knuffle Bunny really get mixed up with another little girl's bunny at school?

"Everything in the story is true except for the parts I made up," Mr. Willems says.

And does Trixie really look like the Trixie in the book?

"She's less inky," he says of his daughter.

Mr. Willems, 40, will be talking about his best-selling picture books, including his Pigeon and Elephant & Piggie books, on Sunday at BooksmArt at the Dallas Museum of Art.

While the former Sesame Street writer and animator makes it all seem easy now, his first book, Don't Let the Pigeon Drive the Bus!, was rejected by many publishing houses during a five-year period for being "unusual." Finally, an editor at Hyperion decided that unusual was good.

Since then, Mr. Willems has won the Caldecott Honor for that book and for Knuffle Bunny: A Cautionary Tale and Knuffle Bunny Too: A Case of Mistaken Identity. His latest Pigeon book inspired 13,000 kids to write in, guessing the title that began The Pigeon Wants a ... as part of a nationwide campaign. The book, The Pigeon Wants a Puppy, came out Tuesday, on the Pigeon's birthday, and the winner of the contest received sets of Mr. Willems' books for himself and his school library.

So, what gave Mr. Willems the confidence to continue in the face of years of rejection?

Probably the same stubbornness that caused him to pursue art long after his art teacher threw away his cartoons.

"My teacher would say: 'This is art class. This is not time to play around.' "

He quit art class. But he continued drawing and eventually went to New York University's Tisch School of the Arts to study animation.

From the beginning, his goal in drawing has been to find a Peanuts-type simplicity, he says.

"As a child, I wanted Charles Schulz's job."

Pigeon, who never gets what he wants (or never wants what he gets), has a bit of the frustrated Charlie Brown about him. But Pigeon is also very much his own bird. Whereas Charlie Brown would agonize like a cartoon Hamlet over whether or not to kick the football or pursue the redheaded girl, Pigeon acts without thinking, with the humor hitting about the time his brain catches up to what he's saying.

Artistically, Mr. Willems designed Pigeon with as few lines as he could.

"It's a rule for me in my books that every character can be reasonably drawn by a 5-year-old," he says. "I want my books to be played with. I want kids to infringe on my copyright just as I made Charlie Brown and Snoopy as a kid, because I want kids to write and express themselves."

With that in mind, he plans to teach the youngsters who attend BooksmArt how to draw Pigeon.

Back home, he says, his daughter, Trixie, draws and writes her own books, too. He notes that she has a cool one about a superheroine called Draw and Erase Girl, who can draw things that come to life and erase them into oblivion.

So what does Trixie think of her dad's books, particularly the ones about her?

"I think she thinks her own books are better than mine," he says. "But she thinks for a grown-up they're not so bad."

Sunday at 3 p.m. at the Dallas Museum of Art, 1717 N. Harwood St. 214-922-1818. www.dallasmuseumofart.org.

{TriRight} $16, $10 students.

DID YOU KNOW?

Mo Willems came up with the distinctive look of the Knuffle Bunny books, in which cartoon characters are superimposed on photos of his Brooklyn neighborhood, because he dislikes drawing backgrounds.

"It ended up being a lot more work because I had to go in and digitally remove all the air conditioners and garbage cans from the photographs," he says. And yet, he adds, it was worth it.

"Philosophically, the photographs lend a quality of reality that feeds the premise that the small stories that happen to children are worth telling."

For more on Mr. Willems, visit www.pigeon

presents.com.