Before drawing his own cartoons, Edwing was the uncredited writer for many of Don Martin's cartoon gags. During Don Martin's final decade with "Mad", Edwing began receiving a writer's byline for many of Martin's cartoons, as well as new material from Martin's paperback books. An example from 1986 is "Early One Evening In Las Vegas," in which a man finds that the only way to summon the fire department is to put a dollar bill in an alarm box which is built like a gambler's slot machine. With the exception of a single page of art, Edwing was exclusively a writer at "Mad" for more than a dozen years before becoming an occasional illustrative contributor in the early 1980s. After Martin left "Mad" in late 1987, Edwing effectively replaced him as the magazine's one-page gag cartoonist.