"Timmy Failure: Mistakes Were Made,” the first kids’ book by “Pearls Before Swine” creator Stephan Pastis. (Deb Lindsey/For The Washington Post)

Cartoonist Stephan Pastis thinks there’s one thing that makes him well-prepared for his new career as an author of illustrated kids’ books.

“I’ve never been a good artist,” confesses Pastis, whose style of drawing uses clean, bold lines. Drawing for books lets him rely more on the words.

Pastis, who created the popular “Pearls Before Swine” comic strip, is too modest about his own talents. Which perhaps makes him the polar opposite of his new creation, little Timmy Failure. Timmy is a boy detective who, while looking for clues, remains absolutely clueless.

“I have an unreliable narrator,” Pastis says of the lead character in the new book, “Timmy Failure: Mistakes Were Made.” “I have to remind myself every chapter: He gets everything wrong.”

Timmy Failure’s name fits him perfectly. Timmy is, in his own mind, “the founder, president and CEO of the best detective agency in town, probably the nation.” But the more obvious the clues seem to be in front of him — hints that most young readers will quickly pick up — the more likely Timmy is to miss or misread them completely.

Cartoonist Stephan Pastis is trying a longer form with his first kids’ book, “Timmy Failure: Mistakes Were Made,” which follows a likable but clueless boy detective. (Susan Young Photography)

Yet Pastis is smart enough to also make Timmy likable. Timmy is an only child who lives with his mom, but he doesn’t have a dad or any truly close human friends in his life. His best pal is Total, a sidekick who happens to weigh 1,500 pounds. Because he’s a polar bear. The catch: Total may or may not be real.

“I leave that . . . up to the reader,” Pastis says of whether Total is real or imaginary. The forever-hungry polar bear is real enough to Timmy, which — as with the tiger in “Calvin and Hobbes” — is what really matters. Total’s presence is a reminder of Timmy’s loneliness, which only makes us like the young detective more.

Pastis wasn’t necessarily looking to write children’s books. Drawing “Pearls Before Swine” keeps him busy: It appears in more than 650 newspapers and has been collected in books. But his agent suggested he try a children’s book, and Pastis is glad he did.

“Novel writing is so freeing,” Pastis says. “Writing for comic strips is restricting. I only have three panels to say what I want to say.”

Pastis is also very careful in how he draws Timmy. Every part of how he looks is done to create a character. For example, one of Timmy’s eyes is also looking slightly off-center, to match the boy’s approach to life. In that way, Pastis says, “I have the ability to convey what I want to, emotionally.”

In other words, Pastis may not be a “good artist” — but he is one great illustrator.