Marvel titles on which he worked included Amazing Spider-Man, The Incredible Hulk, Iron Man, Captain America, Dr. Strange, Savage Sword Of Conan, The Rampaging Hulk, and Transformers; along with team books such as Avengers, Defenders and Invaders. His signature work for Marvel may have been Obnoxio the Clown vs. The X-Men, on which did both art and story.
At DC, Kupperberg worked on Justice League of America, Warlord, Fury Of Firestorm, Cops, Dragonlance, and Blue Devil.
He also did newspaper strip work on Howard the Duck, The Incredible Hulk, and Little Orphan Annie.
He taught at the School of Visual Arts in New York City.
Kupperberg was 62.