Shaun Simon is the former keyboardist for the New Jersey band Pencey Prep, which he founded with Frank Iero and John McGuire. Following the band's breakup in 2002, he accompanied Gerard Way's band, My Chemical Romance, on tour. It was while on tour that many of the ideas for the Killjoys comic book took shape. At the 2012 New York Comic Con, it was announced that a first look at the series would be released on 2013's Free Comic Book Day. The series is drawn by artist Becky Cloonan and edited by Sierra Hahn. Simon has also worked outside the comics medium and was the winner of the Preditors & Editors readers poll for his flash fiction story "Snowman." The author lives in Montclair, New Jersey.