LOS ANGELES -- Cartoonist Henry "Hank" Ketcham, who created the "Dennis the Menace" comic strip after his wife complained that their young son named Dennis was indeed a menace, has died at home in Carmel, California, Reuters reported on Friday. He was 81 years old.

Ketcham, who had been battling cancer, died of a heart attack on Thursday night, spokeswoman Linda Dozoretz said.

His creation became one of the world's most popular comic strips and Dennis became a tow-haired, freckle-faced symbol of mischievous youth. The boy, who was forever five years old, turned 50 on March 12.

In an anniversary interview with Reuters, Ketcham recalled how one editor warned him shortly after he started that he might soon be looking for work. "I don't see how it can last," the editor said, adding: "There's only so much you can say about a 5-year-old kid."

The strip is carried in more than 1,000 newspapers in 48 countries and in 19 different languages. There have been movies based on it, and a successful TV series starring Jay North. In addition, more than 50 million "Dennis the Menace" books have been sold. The Seattle-born Ketcham called his autobiography "the merchant of Dennis."

Although in failing heath, Ketcham presided over the day-to-day activities of the strip, working with two artists, Marcus Hamilton and Ronald Ferdinand, via fax and phone. His spokeswoman, Linda Dozoretz, said the strip will continue to be drawn by the two artists Ketcham worked with for so many years.

A University of Washington dropout, Ketcham worked as an animator for Walter Lantz, creator of "Woody Woodpecker," and for Walt Disney, where he helped draw "Pinocchio," "Bambi" and "Fantasia." He joined the Navy and after World War II drew for the best magazines of the day: ***Collier's, The Saturday Evening Post, Ladies' Home Journal*** and ***The New Yorker***.

He got the idea for "Dennis the Menace" when his first wife, Alice Louise Mahar Ketcham, stormed into the room where he was working and declared of their then four-year-old, "Your son Dennis is a menace."

"So I started out with a name and I gave him a mother and a father and a dog and a pal, Joey. The neighbors, the Wilsons, became surrogate grandparents and I set the whole thing in Wichita, Kan., and as a result I got made an honorary mayor of Wichita. I made it there because Henry Mitchell, Dennis's father, is an aeronautical engineer and there are firms doing that there," Ketcham told Reuters in an interview last March.

Cartoon Family Name Came From Phone Book

The strip made its debut on March 12, 1951 in 16 newspapers. Ketcham said the cartoon family surname of Mitchell came from a phone book. The name of Mr. Wilson, the easily irked neighbor, came from a school teacher Ketcham had.

Ketcham's Dennis was always a little boy who never aged, lost his freckles, learned to read or write or do anything that was not cute or funny. But Ketcham said he did put in signs that the world around him had changed, although barely. In the background of the strip, you can see every so often a computer, a palm pilot, a television and a skateboard.

Ketcham said he was able to do the strip 365 days a year without ever having to repeat himself -- that often. Every so often he thinks he may have done a panel similar to one he did a few years ago.

"I just drew from my friends and family and I am thankful that someone knows about Dennis. A writer writes for himself and doesn't realize that people are following your every move," he said.