In a statement Monday, Mars family said the actor died Saturday of pancreatic cancer at his home in Grenada Hills.
In Brooks' 1968 romp "The Producers," Mars co-starred as Franz Liebkind, a Nazi enthusiast whose play, "Springtime for Hitler," is the basis for a scheme by two conniving showmen (Zero Mostel and Gene Wilder) to bilk investors by putting on a surefire Broadway flop.
Brooks cast Mars again in 1974's "Young Frankenstein" as the constable poking around the castle grounds on the trail of mad scientist Wilder's monster.
In both films, the Chicago-born Mars demonstrated his talent for vocal farce, lending over-the-top German accents to the characters.
Mars' nearly 50-year career included a long list of voice credits, including "The Little Mermaid," ''The Jetsons" and the "The Land Before Time" movies and TV series.
Among Mars' other film credits were Woody Allen's "Radio Days" and "Shadows and Fog," and Peter Bogdanovich's "What's Up, Doc." His extensive television work featured regular roles on "Malcolm in the Middle," ''Fernwood Tonight" and the 1960s series "He & She."
On stage, Mars appeared in such plays as "The Affair" and "Anything Goes."
Mars is survived by two daughters, Susannah Mars Johnson and Rebecca Mars Tipton, and six grandchildren.
A private funeral service was planned.