Rex Larson was a poacher in the Gotham Girls series. Rex setted up a smuggling ring where they illegal trade rare and endangered animals. He hired two henchmen to help keep this ring afloat. At some point, Rex Larson caught Zatanna's white tiger and planned on selling it. Zatanna teamed up with Catwoman to defeat Rex and free their tiger. Zatanna used her magic to distract Larson while she frees the tiger. Rex grabbed his shotgun and was about to shoot Zatannna. Catwoman knocked him out and Zatanna locked Rex in a tiger's cage to be delivered to police custody.