Bikuni

was the leader of a group of yōkai in control of the eastern mountains.

History
Bikuni and his army went up against an army of imps led by Jaken and Bikuni personally faced against Jaken himself. Bikuni's strength was much greater than Jaken's and he attempted to eat his enemy. Binkuni would have succeeded had Sesshōmaru not appeared at that very moment. He demanded both armies remove themselves from the road and get out of his way. Bikuni apparently did not hear or did not dare comply with Sesshōmaru. This caused an impatient Sesshōmaru to slaughter both Bikuni and his entire army. Jaken, however, ordered his troops to clear a way for their unwitting savior. Jaken was so impressed by the stranger that he abandoned his own vassals to follow Sesshōmaru from that day forward.

Trivia

 * Bikuni's only appearance is Jaken's flashback of his life before he meets Sesshōmaru.