Will Elder, whose frantic, gag-filled illustrations helped to define the comic identity of Mad magazine and who was a creator of the Playboy cartoon serial “Little Annie Fanny,” died Wednesday in Rockleigh, N.J. He was 86.

The cause was Parkinson’s disease, said Gary VandenBergh, his son-in-law.

A dead-on caricaturist with an anarchic sense of humor, Mr. Elder stuffed the backgrounds of his Madison Avenue parodies and comic-strip spoofs with inane puns, silly signs and weird characters doing strange things.

“That approach to humor seeped into the rest of the magazine and the DNA of its contributors,” said John Ficarra, the editor of Mad. “It set the tone for the entire magazine and created a look that endures to this day.”

Mr. Elder called these background fillers “chicken fat,” explaining that they were “the part of the strip that gave it some flavor but did little to advance the story line.” This layered, free-for-all approach influenced the cartoons of R. Crumb and films like “Airplane!” and the “Naked Gun” series.