"Grimjack" began as a backup feature in issue 10 of the comic book "Starslayer". The character of Grimjack was created by John Ostrander and Timothy Truman, but the setting, the pan-dimensional city of Cynosure, predates the character. The "Grimjack" backup story was very popular with the readers of "Starslayer", and First Comics decided to give the character his own title. The GrimJack back-up story ran from issue 10 to 17. Grimjack guest-starred in the main "Starslayer" story in issue 18, in July 1984.