Tailed Beasts

The tailed beasts (尾獣, bijū), sometimes referred to as "Chakra Monsters" (チャクラのバケモノ, Chakura no Bakemono), are the nine titanic living forms of chakra created by the Sage of Six Paths out of the chakra from the Ten-Tails. They are differentiated by the number of tails they have, ranging from one to nine. 
Shukaku (One Tails)
Matatabi (Two Tails)
Isobu (Three Tails)
Son Gokū (Four Tails)
Kokuō (Five Tails)
Saiken (Six Tails)
Chōmei (Seven Tails)
Gyūki (Eight Tails)
Kurama (Nine Tails)