Happy Pig Day!, the latest in the hugely popular Elephant and Piggie picture book series by author and illustrator Mo Willems was released last month. The cartoonist recently spoke with Jeff Labrecque at Entertainment Weekly and discussed the genesis of his two quirky main characters. “Elephant and Piggie are the first characters that I created that I intended for multiple books. I really developed them almost in the way that you would develop television. I knew that they were going to have to carry a lot of weight…I knew there were things that I hadn’t imagined that they were still going to have to handle,” Willems explained.

“Elephant was the first character and I was drawing and doodling proto-versions of him for like two or three years. Never quite sure why or how I would use it. And then when I came to the idea of early readers, it struck me as very funny because there are sort of two [theories] of how you teach kids to read. The whole word, that is to say the kid hears the word elephant, they write ‘LFant,’ and that’s acceptable because at least they’re learning the grammar. And then there’s this other argument that says, ‘No, you just have to do it by rote memorization.’ And elephant is always the word that is used by both sides of this argument. So I thought it was really funny that you kind of have the hardest word to spell and the most controversial word in spelling as the star of a series. It felt right. And I think that Elephant’s kind of closer to me: you know, the glass is half full of poison kind of guy. And Piggie, there’s a bit of my daughter, there’s a bit of my wife there. Like anything, I don’t think anybody aspires to be either Elephant or Piggie; you aspire to be them at their best when they work together.”

When asked why Elephant has a name, yet Piggie does not, Willems said: “…[T]he more I thought about Piggie, she is so essentially who she is, she can’t be given a name. A name only complicates her. Elephant is complex in a way. He wears glasses, he has a name, he’s hiding behind stuff because he’s unsure. But Piggie has nothing to hide, so her having a name would dilute that essential Piggieness of her. She’s purely who she is. So it just seems that that’s the way to do it.”

Another one of the author’s beloved characters, Pigeon, from Don’t Let the Pigeon Drive the Bus! made his digital debut last week with the release of Don’t Let the Pigeon Run This App!, now available for the iPhone and iPad.