Murray, an educator-turned-children's author from Canada, is still getting used to the ruckus over two books he co-wrote. They feature "Walter the Farting Dog," a flatulent pooch whose little problem saves the day time and time again.
The content may seem quirky and even off-color to some. But these days, potty humor is big in the world of popular children's literature - from the "Captain Underpants" series to such best-selling titles as "Zombie Butts from Uranus!"
Parents jokingly call the genre the kid's version of pulp fiction - or "poop fiction."
"You gotta give kids something they want to read," says Murray, who firmly believes that his smelly but well-meaning protagonist has become an ambassador for literacy.
"Now he's the people's dog," Murray says. "And I'm just his agent."
It would seem that kids agree, since the genre's books regularly appear on children's best-seller lists.
Derek Morgan, an 11-year-old Chicagoan, recently picked up the second Walter picture book, subtitled "Trouble at the Yard Sale."
"If you want to laugh," the fifth-grader said at one of Murray's book store appearances, "read this book."
Kaylee Paul, a 6-year-old from Riverside, Calif., has latched onto Captain Underpants, a cross between a cartoon and a chapter book, written by author Dav Pilkey. Her favorite is about the "Big, Bad Battle of the Bionic Booger Boy."
"I like to read it every day. I really, really do," Kaylee says. She's been inspired to create her own cartoon series - "about a chubby man that farts everywhere he goes," she explains, then giggles.
Kaylee's parents say they originally bought her the Captain Underpants stories because, as an early reader, picture books became too easy. She likes the series so much that now her dad, Stan Paul, sometimes has to tell her "That's enough reading for today."
Editors at Scholastic Inc., which publishes Captain Underpants, say that's the goal - especially when it comes to kids who are "reluctant readers."
"For many, many kids, this is the first book they read that starts them on a path of reading," says Barbara Marcus, president of Scholastic's children's books division.
Librarians call such stories "book hooks," says Barbara Genco, immediate past president of Association of Library Services to Children.
Scholastic also publishes "Zombie Butts from Uranus!" by Andy Griffiths. It's the sequel to "The Day My Butt Went Psycho," a story about a 12-year-old named Zack whose back side is prone to detaching itself, running away and causing trouble.
Gail Glover, a mom from Port Crane, N.Y., bought the latter book for 9-year-old son Robbie, but later wondered if she'd made a mistake.
Among her objections were "descriptions of bodily functions that made my hair curl."
"But of course, they solicited howls of laughter from my son," Glover says, chalking it up to "a rite of passage in the development of his sense of humor."
She notes, however, that her son still likes to read the "classics" - including the Harry Potter and "Lord of the Rings" books, as well as works by authors Roald Dahl and Jack London.
Those are the books he should be reading, say some parents who've persuaded their school libraries to take Captain Underpants and other titles off their shelves. Some educators agree.
"I don't want to be a prude about it," says Sister St. John Delany, a nun who heads the School of Education at New York's Pace University. "I just don't think kids need to be exposed to that kind of language."
Murray - who's worked in the education field as an administrator and consultant - is well aware of the "two camps," those who love Walter and those who turn up their noses.
But the author from Fredericton, New Brunswick, still hopes his books become a classic of another breed.
The inspiration for Walter came from a story co-author William Kotzwinkle told Murray about a real 150-pound bull mastiff whose troubles with gas came from the beer and doughnuts his owners fed him.
While they wrote the first book more than a decade ago, it took several more years to persuade a publisher to print it.
Now each book carries a simple dedication: "For everyone who's ever felt misjudged or misunderstood."
By Martha Irvine