At DC Comics, Hannigan redesigned the Brainiac character into a chromed, more robotic form. He pencilled the covers on Batman in a lengthy run that spanned the majority of 1983–1985 with Don Newton providing the interior art. Hannigan and writer Mike Grell launched the first Green Arrow ongoing series in February 1988. The Batman: Legends of the Dark Knight series began in November 1989 with the five-part "Shaman" storyline by Hannigan and writer Dennis O'Neil. He both wrote and illustrated the three-issue prestige format series Skull & Bones for DC in 1992.