Gyūki

The Eight-Tailed Beast is currently one of the two remaining Tailed Beasts that were not extracted by Akatsuki, the other one being the Nine-Tailed Demon Fox. The Jinchūriki, Kira Hachi, is a black, musclebound Cloud shinobi, who appears to dislike light. On his right shoulder, he has a tattoo that says "iron"; and on his left cheek, he has a tattoo of a bull's horn (ironically, the Eight-tailed beast has horns like a bull, and the left one is missing). He also carries seven swords. It also seems that he hates being called the host for the Eight-Tailed Beast, and prefers to be referred as "me and that thing".

Abilities
Most of his abilities are still yet unknown, but it has been shown that he uses seven swords in a very peculiar manner. He places one on his neck (right cheek), one in his mouth, one in his left armpit, two in his elbows, one on his right hip and the last one in his right knee. This special maneuver allows him to attack his opponent with great speed and also in a circular faction, like a ball. Also, he is able to put chakra into his blades allowing them to up their power and also re transfer any other chakra being propelled by the opponent. So far, from the manga he has supernormal strength and an unorthodox style of being able to wield 7 swords at the one time. In addition to this he is able to use the Eight-tails' chakra to break illusions, even ones casted from a Mangekyo Sharingan. He is capable of both a partial transformation and a full transformation. The partial transformation grants him with an Eight-tailed demon cloak not unlike Naruto's, but with what appear to be bull horns replacing the fox ears of Naruto's cloak.

Speculation
As most of the other Tailed Beasts seen so far are based upon mythological creatures, it was speculated that this Tailed Beast was based upon the eight-headed and eight-tailed serpent, Yamata no Orochi. However judging by the characteristics he possesses such as his dislike of light it has been speculated that the Eight-Tails is perhaps a mole, others think it might be a bee. But, based on his silouettte, he may also be an octopus of some kind. Some fans believed that Orochimaru was the Eight-Tailed Beast due to his snake-like abilities, however, this was proven false in chapter 408. Recent chapters have revealed that that Eight-Tails is a giant bull with eight tentacle-like tails. He also has control over his inner demon.

Trivia

 * The 8-Tail has an unusual personality, similar to African American urban youth stereotypes (corn rows, jive talk, and rapping). This could also either be a homage or a reference to the Wu-Tang Clan,who are martial art enthusiast. He calls himself the Killer Bee, A old "Wu Tang" Kung Fu movie and group name of Wu Tang Records. Most members and groups of this label get there stage name from the old "Wu Tang" movies (Ex. Method Man, Old Dirty Bastard, Rza, Gza, Killer Bees, and the records labels name itself).