Jinchuuriki NARUTO Images

"Jinchuuriki" meaning the "power of human sacrifice", are those individuals possessing "Bijuu" or tailed demons within their bodies.

The demons themselves are known by the number of tails their body possesses, and each has different characteristics. Shukaku ("Ichibi") is the One-Tailed Tanuki, "Nibi" is the Two-Tailed Cat, "Sanbi" is the Three-Tailed Turtle, "Yonbi" is a Four-Tailed Ape, "Gobi" is a Five-Tailed Horse-Whale, "Rokubi" is a Six-Tailed Gastropod, "Shichibi" is a Seven-Tailed Rhino Beetle, "Hachibi" is the Eight-Tailed Ox-Cephalopod and "Kyuubi" is the Nine-Tailed Fox.

These Bijuu were once all part of an even greater entity known as the "Juubi" or Ten-Tails. The first ninja, the legendary Rikudou Sennin did battle with the Juubi and split its power into nine individual entities using his Izanagi jutsu, which allowed him to alter reality.