Yagura Karatachi

was the jinchūriki of the Three-Tails and the of Kirigakure. When the Three-Tails was captured by Akatsuki, it had no host and roamed out in the wild.

Background
During his time as Mizukage, the village was known as the, mostly because of the barbaric ritual where Academy students kill one another in order to graduate. This practice was discontinued when an entire graduating batch of Academy students were massacred by a young Zabuza Momochi. It is likely that Yagura was the Mizukage whom Zabuza tried to assassinate when he revolted.

Yagura was also known to dispatch Kiri-nin who were suspected of being disloyal to the village immediately (commending and taking Kisame Hoshigaki as his direct subordinate after assassinating Fuguki Suikazan, a traitorous member of the Seven Ninja Swordsmen of the Mist). Yet despite the terror of his reign, he appeared to be kind. Apparently the people of Kiri feared that Yagura was being manipulated, a fear which was confirmed by Ao, who saw through an unnamed genjutsu with his Byakugan, later identified by Kisame as the work of Tobi.

Appearance
Yagura has messy grey hair (brown in the anime), pink pupiless eyes and what seems to be a stitch-like scar running from under his left eye, all the way down his cheek. He wears a grey, sleeveless shirt with the Kirigakure forehead protector attached to the front, short-sleeved mesh armour over which he also wears a green poncho along with a turquoise sash around his waist, paired with a green apron over his pants. He wears a pair of brown boots, and on his back he carries a staff-like pole weapon with uneven sized hooks with a green flower on the larger end.

Abilities
Not much is known about his abilities except that he was presumed to be a powerful shinobi due to him being chosen as the Mizukage, and was also one of the few jinchūriki that were able to fully control his tailed beast. He wielded what seems to be a large staff, with two hooks on each end, one larger than the other, along with a green flower on the larger end.

Nature Transformation
Yagura is able to uses Water Release ninjutsu to create mirrors that reflect enemy attacks.

Shinobi World War Arc
In preparation for the Fourth Shinobi World War, Yagura is resurrected by Kabuto Yakushi to fight against the Allied Shinobi Forces, before being mobilised alongside the other deceased jinchūriki.

As dawn breaks on the second day, it is revealed that Tobi had turned the revived jinchūriki into his own customised Six Paths of Pain, with each having a Rinnegan and Sharingan in place of their left and right eyes respectively. Yagura is later seen traveling together with Tobi, in pursuit of Naruto and Killer B.

When Naruto and Killer B finally appeared and clashed with Tobi, the Jinchūriki went into battle against the two. As Naruto and Killer B dodged Rōshi's assault, they moved in to attack. Yagura countered with his Water Release: Water Mirror Technique, using the water to create tangible reflections of Naruto and Killer B which clashed with the originals and repelled them momentarily. After the initial assault proved ineffective, the revived Jinchūriki unleashed the power of their Tailed Beasts, with Yagura materializing the first tail of the Three-Tails.

Trivia

 * The word means "tower" or "turret". It could also refer to the tombs in the middle ages.