In the graphic novel "Batman and the Monster Men", Maroni lends money to Norman Madison (father of Bruce Wayne's girlfriend Julie Madison) to cover his debts, and to Professor Hugo Strange for his genetic experiments. After Maroni puts pressure on Strange to repay his loan, the mad scientist responds by robbing one of his illegal gambling establishments to steal the money he needs to pay Maroni off. When Maroni realizes Strange might be responsible for the robbery, he sends enforcers to intimidate and threaten him. Strange decides to get rid of Maroni once and for all, and sends another creature to kill him. Maroni is saved by Batman, who as a favor to Julie Madison, forces him to call off her father's debt.