Yonbi Sokou

Yonbi is one of the "bijuu", a tailed beast of the ancient world. The Yonbi was housed inside Roushi, a wandering ninja. It is unknown what animal this bijuu was. Roushi used the Yonbi to create Youton, the Lava Element, a fushion of Earth and Fire Elements.

Sanbi Genbu

Sanbi is one of the "bijuu", a tailed beast of the ancient world. Seeking a way to create a ninja with a large amount of chakra that would be an unstoppable machine, the demons were placed inside shinobi. At some point in the past, it was housed within a ninja from Hidden Mist.

Nibi Nekomata

Nibi is one of the "bijuu", a tailed beast of the ancient world. Seeking a way to create a ninja with a large amount of chakra that would be an unstoppable machine, the Nibi was placed inside Hidden Cloud kunoichi Yugito. Nibi has been refered to as an "ikiryou" or living ghost.

Ichibi Shukaku

Shukaku is one of the "bijuu", a tailed beast of the ancient world. Seeking a way to create a ninja with a large amount of chakra that would be an unstoppable machine, the Kazekage had Shukaku imbued within his unborn son.

Yamato

"Yamato" as he was dubbed by Tsunade, was an elite ANBU who led Team Kakashi when Kakashi was fatigued from battle. Yamato led the team of Sai, Naruto and Sakura to the Grass Country. They were to meet Sasori's spy who was spying on Orochimaru.