Jaryūki was a legendary five headed serpent-like beast that lived in the Underworld. The beast could spit powerful acid. It was believed to exist in Hokkaido during the Meiji period. Gaou, his pack and the original Eight Canine Warriors of Sirius fought and managed to defeat it. As a symbol of their victory, the wolves ate the dragon's body. It's believed that Jaryūki's meat gave the wolves strange powers, explaining their Battougas and other unusual abilities.