Comment by Nonamr on Exquisite Blood: The Heretic Onmyoji - Chapter 41

Kinda called it. "Yamata no orochi" is a famous figure, also known as the 8-headed snake. 

I just wanna add that there is a "yamatohime-no-mikoto" who is known to be the first priestess(and also a princess) who established the Ise shrine.