He first appears in Batman 12, where he's shown to be the younger sibling of Harper Row. This takes place before Batman 1's event hosted by Bruce Wayne. Cullen urges Harper to go out and have a good time, insisting that she worries too much. It's revealed that he's harassed by a gang for being gay when Harper spots a cut on his arm. But Cullen insists she goes. When she comes back, she finds their house ransacked and Cullen beaten up, the word "fag" cut into his hair. Harper matches this with her hair and supports him at school. That night, the group of thugs attack, and Batman saves them. This sparks Harper's obsession with Batman, and giving him a hand.