Mr. Grossman was found dead on Friday morning and was believed to have died of congestive heart failure the previous night, said his son Alex Emanuel Grossman.
A painter, cartoonist, sculptor and artist of the airbrush, Mr. Grossman designed book and record covers and contributed illustrations to a ream of publications, including Rolling Stone, Time, Mother Jones, the Nation, the New York Observer and New York magazine.
He created a comic about a black superhero (Captain Melanin) in the 1960s; received an Academy Award nomination in 1978 for “Jimmy the C,” a claymation short in which President Jimmy Carter sang Ray Charles’s version of “Georgia on My Mind”; and devised the promotional poster for the 1980 satirical disaster film “Airplane!,” painting a jetliner whose fuselage had somehow twisted itself into a knot.
Yet, he was best known as an equal-opportunity caricaturist, targeting cultural figures from Playboy founder Hugh Hefner (partially obscured by a comically large pair of breasts) to tennis player Jimmy Connors (drawn as an infant sticking his tongue out on the court), and tweaking presidents regardless of their political party.
Mr. Grossman transmogrified Ronald Reagan into a Mickey Mouse-like “Ronald Rodent,” painted Carter as an overall-wearing hayseed, and in 2005 drew a controversial cartoon of “Babe Lincoln” for the Nation, inspired by a biography that argued Abraham Lincoln was gay.
He seemed to have a particular fondness for Nixon, who swept into office just as Mr. Grossman’s career was taking off in the late 1960s. For one Watergate-era cover of Britain’s Sunday Times Magazine, Mr. Grossman depicted the president as an overflowing faucet, water plunging out of his steely nostrils. For National Lampoon, he imagined Nixon as an eggplant-nosed Pinocchio, with a Jiminy Cricket-like Henry Kissinger perched atop his proboscis.
While Mr. Grossman’s work was frequently incisive, cartoonist Drew Friedman wrote by email, it also had a whimsical quality that “set him apart from most of his best contemporaries, among them David Levine and Edward Sorel, who were masters at playing up the grotesque.”
In part, the whimsy was a result of Mr. Grossman’s favored tool, the airbrush, which allowed him to effectively sculpt three-dimensional figures out of paint or ink. The technique was later adopted by humorists such as Terry Gilliam of Monty Python, although at the time Mr. Grossman first picked up an airbrush — as a child at his father’s silk-screen printing shop in Brooklyn — the device was not widely used in the art world.
“He made the airbrush an expressive medium, where before it was just an objective tool that commercial artists used to add dimension or take things out of an illustration,” said Steven Heller, a former New York Times art director who co-chairs the MFA design department at the School of Visual Arts in New York. “What Bob did was create a style that just jumped off the page.”
Robert Samuel Grossman was born in Brooklyn on March 1, 1940. His mother worked as a bookkeeper for his father, who painted in his spare time and instilled an appreciation of fine art in Mr. Grossman and his siblings.
Mr. Grossman said he turned toward humor in the 1950s reading Mad magazine, which “appeared like a nearly divine revelation,” he told the Tennessean newspaper. He befriended the magazine’s founding editor, cartoonist Harvey Kurtzman, while studying at Yale University, where he edited the Yale Record humor magazine and graduated in 1961.
One of his designs for the Record, a parody cover of the “Yew Norker,” apparently helped him get a job at the New Yorker magazine, where he said he worked “as a sub-assistant cartoon editor” before becoming a freelance illustrator.
His marriages to Donna Lundvall and Vicki Morgan ended in divorce.
Survivors include his partner of 24 years, Elaine Louie; three children from his first marriage, Michael Grossman Rimbaud and Alex Emanuel Grossman, both of Manhattan, and Leila Grossman of Nashville; a daughter from his second marriage, Anna Grossman Pedicone of Manhattan; two brothers; and five grandchildren.
At the time of his death, Mr. Grossman had just completed an illustrated novel about the “Great Moon Hoax” of 1835, in which the New York Sun reported that winged beings lived on the surface of the moon. Titled “Life on the Moon,” the book is scheduled to be published in 2019.
Mr. Grossman had also written a comic strip, “Twump and Pooty,” lampooning Trump and Russian President Vladimir Putin. The serial followed in the tradition of his series about O-man (a heroic President Barack Obama) and Cap’n Bushy (a flying squirrel modeled after President George H.W. Bush).
He said he just couldn’t resist using fake names for his strips’ famous protagonists.
“The cowardly strategy of not calling people by their right names has been employed since the first fool told a funny story about a bear named Hairy, to avoid getting his head cut off by King Harry,” Mr. Grossman told the Atlantic in 2012.
“And it might possibly be funnier than drearily calling a spade a spade. The art of caricature enchants me for its similar ability to combine truth and falsehood in a strangely appealing way.”