One day in 1950 a little boy named Dennis Ketcham was napping—or so his parents thought. In fact, he was tearing his room apart. "Your son," his mother, Alice, told her husband, Hank, "is a menace." Inspired, Hank Ketcham began to draw. Dennis the Menace, the cartoon Ketcham created, still runs in more than 1,000 newspapers. "For 50 years Hank gave us Dennis," says friend and fellow cartoonist Mell Lazarus, creator of the Momma strip, "and Dennis was our rottenest kid in a very endearing way."

For Ketcham, who died June 1 of heart disease and cancer at age 81 in his Pebble Beach, Calif., home, Dennis—also the basis for numerous TV shows, movies and videos—was more than just a job. The Seattle-born son of a businessman and a writer, he told the Associated Press in March that drawing the Mitchell cartoon family was "a joyful pursuit... trying to ease the pain of front-page news."

But the Mitchells' troubles paled by comparison to those of the Ketchams. Alice died of a drug overdose at 40. Their only child, Dennis, attended boarding school in Connecticut while Ketcham lived in Switzerland with his second wife, Jo Anne Stevens. (He returned to the U.S. in 1977 and settled in California with his third wife, Rolande Praeport, and their children, Scott, now 24, and Dania, 28.)

After a tour in Vietnam with the Marines, the real Dennis, suffering from post-traumatic stress disorder, became increasingly estranged from his father. Hank's relationship with his son, Ketcham told the AP, "was just a chapter that...closed, which unfortunately happens in some families."

But never to the cartoon Mitchells. "Hank's work," says Lazarus, "never changed. He never acknowledged there was danger in the world."