Eleven-Tails

The Eleven-Tails (十一尾, Jūichibi) is a tailed beast created via the bureka experiment. Aku used Ankylosaurus DNA to ensure that he can become and separate from a Eleven-Tailed Ankylosaurus. In order to become it's Jinch ūriki Aku had to separate it from his body and thanks to the friend in the dark he was able to. The Eleven-Tails is eventually defeated and sealed by Poji.