The Yamata no Orochi is a giant demonic dragon from the past that brought destruction to the world. It got its horn cut off by Susanoo, who sealed the dragon onto the Earth's surface with 8 magical swords. Its body is actually Japan itself. It is awakened by Onimaru and used to destroy the world, but is stopped and sealed once more by the combined efforts of a Kaguya-possessed Sayaka (who blocks his heart) and Yaiba's Supreme King Sword (used to cut off his horn).