Raging Tailed Beast

is episode 99 of the Naruto: Shippūden anime.

Synopsis
Yūkimaru summoned the Three-Tails and immobilized it while Guren tried to capture it, but it managed to break free and attack. Kakashi told Naruto to investigate the lake, while they found Rinji and the others. Rinji and his men prepared an ambush, but Hinata, Sakura, and Sai arrived to avert it. Naruto summoned Gamakichi and Gamatatsu and approached the Three-Tails, where they saw Yūkimaru and learnt of his allegiance to Guren. Trying to save Guren, Yūkimaru tried to suppress the Three-Tails once more, before managing to escape with her.