Jack Russell is a werewolf, dubbed Werewolf by Night. Afflicted with a curse that causes him to transform during a full moon, Russell strove to help other monsters in need and hunt monsters that were a danger to others. In order to assist his friend, Ted Sallis, Russell attended a gathering of monster hunters competing for the Bloodstone. Russell worked with Elsa Bloodstone to free Sallis, but in doing so exposed himself as a monster. Verussa Bloodstone captured him and forced him to transform, inadvertently unleashing the werewolf by night on her own forces. Russell spared Elsa and fled, reuniting with Sallis.