Don Martin, 68, the longtime Mad magazine cartoonist who drew an assortment of wild-haired characters, punctuating the grotesque action with wacky words like SPLOP! and POIT!!, died of cancer Jan. 7 at a hospital here.

During his 30-odd years as a Mad contributor, Mr. Martin based his humor on misery and misfortune, cracking "sick" jokes. The magazine dubbed him "Mad's Maddest Cartoonist."

The guy poisoning pigeons in the park--"I hate pigeons"--winds up killing the people who gather around to sample his scrumptious popcorn. Mona Lisa, as the reader realizes only in the last frame of the strip, is sitting on a toilet. Hapless boobs with big feet get squashed in all manner of ways.

"There's always been physical suffering in comedy," he once said. "Even ancient clowns kicked each other in the seat of the pants or hit each other over the head. It's the same thing in our time, just a little stronger."

The cartoons had a vocabulary all their own. "SHKLIP" was the sound made when construction workers tossed concrete at each other. "SPLOP" described a surgeon throwing body parts into a doggie bag. "FAGROON" came from a collapsing skyscraper.

His license plate read "SHTOINK."

"Is it funny? That's the only test I know when it comes to cartooning," Mr. Martin once said. "Not whether it's sick or whether it's going to ruin people's values or morals. You only have to ask a simple question: Is it funny?"

His twisted approach influenced generations of younger cartoonists.

"Don Martin was the one who really stood out," Gary "The Far Side" Larson told the Miami Herald in a story published in 1990. "I really always loved his work. He was such a great artist."

Mr. Martin left Mad magazine in 1987 after a falling-out with its publisher, the late William Gaines, and accepted a job at Cracked, a competitor.

Mr. Martin chafed at the tradition that Mad, like most publications, retained all rights to reprint and profit from his work that it used, paying him on a freelance basis. But he put out paperbacks of cartoons not published in the magazine, eventually selling more than 7 million copies.

He drew despite a degenerative eye condition that forced him to undergo cornea transplants, wear special, highly uncomfortable contact lenses and use a magnifying glass while drawing.

"He was a shy and retiring sort of guy, considering he drew a comic strip that was crazy," said longtime friend Laurence Donovan.

Mr. Martin was born in Clifton, N.J., and began his undergraduate work at the Newark Institute. He earned a fine arts degree from the Philadelphia Academy of Fine Arts. He began submitting drawings to the fledgling Mad magazine in the mid-1950s.