Blue B

He was the previous jinchūriki of the Eight-Tailed Giant Ox.

Background
He did not have control over the Eight-Tails, as it killed many Kumogakure ninja including Motoi's father. The Third Raikage extracted the Eight-Tails, resulting in the jinchūriki's death. The Eight-Tails was immediately sealed in Killer B.

Appearance
He had long half-black and half-white hair, dark eyes and a tattoo in the shape of a diamond on the right side of his face. He wore a Kumogakure flak jacket and carried a fairly large sword.

Trivia

 * This person's status as a jinchūriki suggests he might have had relationships to former bearers of the title of "Raikage" (as per tradition) or simply a competent enough shinobi expected to use the tailed beast's power effectively; which he ultimately failed in.