Born in Brooklyn, New York City, Krantz graduated from Columbia University and went on to serve in the U.S. Army Air Forces in the Pacific during World War II as a second lieutenant.

After firing Shamus Culhane from the animator's supervising director job on Rocket Robin Hood, director Ralph Bakshi and background artist Johnnie Vita were brought to Toronto, not knowing that Krantz and producer Al Guest were in the middle of a lawsuit.

Failing to reach a settlement with Guest, Krantz told Bakshi to grab the series' model sheets and return to the United States.

[5] Fritz the Cat was released on April 12, 1972, opening in Hollywood and Washington, D.C.[6] A major hit, it became the most successful independent animated feature of all time.

Bakshi found Krantz's claims dubious, as the producer had recently purchased a new BMW and a mansion in Beverly Hills.

[10] The couple had two sons, including film and television writer, director and producer Tony Krantz.