What is a bijuu?

Answer 1

The bijuu are creatures of great power and destruction, and all the ninja nations coveted that power and sought to make it their own as weapons. To that end the various bijuu were captured and the ninja nations attempted to use that power. This unimaginable power proves difficult to manage however, requiring literal sacrifices to gain control. Several jutsu variations have been used to seal a bijuu within a human. Yondaime Hokage used his Shiki Fuujin technique to capture the rampaging Kyuubi and seal it within Naruto. The jutsu had a high price, resulting in the death of the jutsu's user, Yondaime Hokage. The Ichibi Shukaku was sealed into the unborn body of Gaara, with the sacrifice taking the form of his mother, who died as a result of his birth.

even if by a little.

Answer 2

They are, in ascending order

The Ichibi, Shukaku, a giant raccoon made of sand, used to be sealed in our favorite Sand Ninja, Gaara

The Nibi, Bakeneko, a cat made of hot-as-hell blue fire, used to be sealed in Yugito Nii of the Cloud Village, now deceased.

The Sanbi, Kyodaigame, a huge honkin' turtle with lobster tails, used to be sealed in Yagura, the Fourth Mizukage, now deceased

The Yonbi, Saru, a great hairy monkey that flung lava rather than feces,used to be sealed in Roushi of the Rock Village, now deceased

The Gobi, Irukauma, a bizzare-o dolphin horse hybrid, used to be sealed in Han of the Rock Village, now deceased

The Rokubi, Namekuji, a giant slug that spits out bubbles, used to be sealed in Utakata of the Mist Village, now deceased

The Nanabi, Kabutomushi, a gigantic beetle with six wings and a torpedo stinger, used to be sealed in Fuu of the Waterfall Village, now deceased.

The Hachibi, Ushi-Oni, a towering montrosity of a bull with octopus tentacles!!! Sealed in the mad ninja ma jinja gangsta playa, Kirabi.

Kyubi, Kitsune, sealed a way int he guy we all know and love, who will keep fighting and become the world's greates Hokage BELIEVE IT !!!!