Chibaku Tensei (episode)

is episode 167 of the Naruto: Shippuden anime.

Synopsis
Naruto enters his Four-Tailed form and attacks Pain, who manages to repel his attacks. Angered even further, Naruto continues his transformation into a Six-Tailed form. Pain decides to fall back and activate his Chibaku Tensei technique, creating a miniature moon in the sky formed from the earth, which traps Naruto inside. However, Naruto breaks free of it, now in an Eight-Tailed form. Consumed in hate, Naruto prepares to completely let the fox free, but the Fourth Hokage appears and stops him.