He is best known for his work on the DC Comics characters Sgt. Rock and Hawkman.
Kubert's other creations include the comic books Tor, Son of Sinbad, and Viking Prince, and, with writer Robin Moore, the comic strip Tales of the Green Beret.
He emigrated to Brooklyn, New York City, United States, at age two months with his parents and his two-and-a-half-year-old sister Ida.
Kubert attended Manhattan's High School of Music and Art.