Hagoromo's Brother

[PabloEscobar]

Is the Ancestor of Orochimaru, who happens to be the master of Yamato No Orochi, just like in Japanese Methology.

 

[Seventh Sama]

Or he died during the fight with the juubi....

 

[Eternal Gennin]

Might be. Might not be. We won't know until we read in the manga.