Isis was Catwoman's favorite pet cat. She was well trained and even helped Catwoman in heists. Once Isis ran away from Selina and ended up being cought by a scientist named Milo and he injected her with a virus. She even infected Catwoman by scratching her. The two of them would have died had it not been for Batman. Batman found the cure and gave it to Isis and Selina. However Selina was still unable to find Isis. Batman then brought Isis back to Selina's home and the two of them were happy to be reunited.