Talk:King Taijitu/@comment-2163079-20170721013818/@comment-4010415-20170721023800

The eight-headed fused King Taijitu in the manga is a reference to Yamata no Orochi, not the hydra. This is made clear when Blake mentions a story about a sword being found inside of an eight-headed snake, referencing the fact that the sword Kusanagi was found inside of Orochi in the story.

The King Taijitu itself on its own is just a two-headed snake. They didn't really say anything about what it's based on, just that they made it a two-headed snake and named it King Taijitu after the black and white King Snake and the Taijitu symbol (YinYang).