Yagura Karatachi

was the jinchūriki of the Three-Tailed Giant Turtle and the of Kirigakure. When the Three-Tails was captured by Akatsuki, it had no host and roamed out in the wild. The reason why the Three-Tails was removed from Yagura is unknown.

History
During his time as Mizukage, until the massacre of Academy Students by a young Zabuza Momochi, the village was known as the, due mostly because of the barbaric ritual where Academy students kill one another for graduation. It is likely that Yagura was the Mizukage who Zabuza tried to assassinate.

Despite the terror of his reign, he appears to be kind. Apparently the people of Kirigakure fear that Yagura was being manipulated, a fear which was confirmed by Ao, who saw through an unnamed genjutsu with his Byakugan.

Eventually, the Three-Tailed Beast was removed from Yagura for unknown reasons, and the beast was allowed to roam free. With that, Yagura's life and reign came to an end.

Trivia

 * Because Yūkimaru has some control over the Three-Tails, and because he has some resemblance to Yagura, it is speculated that they have some connection to each other; however, Yūkimaru is an anime-only character that does not appear in the manga.
 * Yagura is one of only four people said to be able to truly control a tailed beast, the others being Hashirama Senju, Madara Uchiha, and Killer Bee.
 * Yagura is one of two jinchūriki known to have been a Kage, the other being Gaara.