Choumei

Choumei, more commonly known as the Seven-Tails or Nanabi, is a tailed beast sealed within Fuu from Takigakure. It was captured, extracted, and sealed by the Akatsuki. In the anime, Choumei is indicated to have been one of the two tailed beasts that Akatsuki captured before the start of Shippuden. (Source: Narutopedia)