Akimaru

Though often just referred to as Akimaru, each head seems to respond to different names individually. The one on the left, who appears to be much more reserved, goes by Aki. While the one on the right, who's much more friendly and outgoing, goes by Maru. Both seem capable of controlling the whole body, except the other's head. The only one capable of moving the head and facial movements is whoever that face/head belongs to. The two reside deep in a forest that humans often refer to as the "Forest of Misfortune." They are one of the many guardians, spending a lot of their time sleeping in front of a sacred shrine. Should any threat get too close to the shrine, they'll be awoken immediately and will guard the place with their life.