Gantz graduated from The High School of Music & Art in New York City, the National Academy of Design at Iowa State University.
[2] He penciled and inked comic books in the 1940s and 1950s, working for Timely Comics's humor features like Gandy Goose, Sharpy Fox, Mighty Mouse, Patsy Walker, and Super Rabbit.
Don Q. was a satirical strip featuring characters from Miguel de Cervantes' Don Quixote, with commentary on contemporary politics and daily life.
[2] Gantz authored the editorial cartoon Gantz' Glances for Newsday from 1997 to 1999;[2] he received the National Cartoonists Society Newspaper Panel Cartoon Award in 1997 for it.
In retirement, Gantz wrote and drew The History of Jews in America, and devoted much of his time to sculpture.