The tailed beasts [bijū] are nine giant demons which signifies the plot of Naruto series. They differ by the number of tails they have, from one to nine. The tailed beasts are large, living forms of "Chakra Monsters" (Chakura no Bakemono), giving them power that far outmatches most shinobi. However, this immense strength is tempered due to their bestial nature, which restricts them from being intelligent enough to use it effectively.
When the tailed beasts are sealed within humans, they are able to benefit from the knowledge of their hosts, giving them the ability to speak and better utilize their powers. Akatsuki has been capturing the tailed beasts and their hosts, and as of the Fourth Great Shinobi World War possess seven of the nine beasts. [source]
For those who love watching the anime, I’m sure you are familiar with the tailed beast. In Naruto there are actually 9 tailed beasts mentioned. But the original of the entire demon beast is the Ten-tailed beast. The ten-tailed or Jūbi is the ancient demon of the series. It is believed that all the chakras from the nine beasts are divided and came from the ten-tailed beast. The Akatsuki – a group of missing ninjas are the ones who collect the beasts for their own goal, and that is for world dominion (I’ll explain further in the next post ^^) Okay that’s it! Let us know more about the tailed-beast and its corresponding jinchūriki [host].
The One-tailed Shukaku [Ichibi] is the tailed beast that was sealed in Gaara. Actually Gaara was the third jinchūriki of the one-tailed beast. Gaara is from the Hidden Village Land of Wind. [Sunagakure literally means "Village Hidden in the Sand"] and he was the fifth Kazekage at a very young age [15-16 years old]. Gaara became a Chūnin at the age of 14 and a Wind type user. He can do a lot of Jutsu.
He can manipulate the sand and used it for varied purposes. I was wondering about Gaara’s eyes why it has dark circles around it. The reason behind it is insomnia caused by the one tailed beast, actually it was since birth. He appeared to be antagonist at the first part of the series but later on he was one of the protagonists. Gaara crated a Kanji “love” on the left side of his forehead which is a symbol of Yashamaru's [uncle] betrayal.
The monkey beast is the four-tailed beast [Yonbi no Saru] sealed within Roshi of Iwagakure literally means Village Hidden in the Rocks. He is also a jinchūriki at a young age and it is said that he left his hometown in order to fully develop the power of tailed beast inside him. He is a Nature type user, he can do Lava Release ninjutsu which is a combination of Fire and Earth based chakra.The Four tailed Monkey is a tailed beast sealed within Rōshi of Iwagakure.
The Dolphin Horse beast [Gobi no Irukauma] was sealed within Han of Iwagakure. Han appears in Manga only chapter #420. He can do steam based ninjutsu. He is heavily armored which extends all the way to the bottom of his face, covering it. The armor is called “steam armor”. Actually he was the largest jinchūriki (physically), he’s taller than Killer Bee also.
The Slug beast [Rokubi no Namekuji] sealed within Utakata, a shinobi from Kirigakure (Village Hidden in the Mist). Utakata is a missing nin of Kirigakure and fighting those hunter nin sent from his village to retrieve him. I like his Bubble techniques. He appeared in Naruto Shippuden Episode #144.
The Horned Beetle beast[ Nanabi no Kabutomushi] sealed within Fū from Takigakure (literally means Village Hidden in a Waterfall). She appears in manga only chapter #420.
A Giant-Ox beast [Hachibi no Kyogyū] sealed within Killer Bee of Kumogakure (literally means Village Hidden in the Clouds). Actually this beast has a muscular upper body structure and consist of eight tentacles like an octopus. (That’s why I wonder in the tv series it appears to be like an octopus). Killer Bee is the younger brother of the Fourth Raikage. He also claimed to be the perfect host and can fully control his tailed beast. An extremely powerful ninja and does a lot of amazing jutsu (many to mention). He’s kinda funny though, he expresses his pride through songs in a rap style. He even quoted Muhammad Ali’s famous line “float like a butterfly, sting like a bee”.
The Demon Fox beast [Kyūbi no Yōko] sealed within Naruto of Konohagakure (literally means Village Hidden among Tree Leaves). The beast is the most powerful among other tailed-beasts. Naruto is the central character of the series, the son of the fourth Hokage Minato Namikaze and Kushina Uzumaki. Naruto is the second jinchūriki when his mother died after giving birth. Actually Kushina was the first jinchūriki of the nine-tailed beast. Naruto is naïve and sluggish to learn jutsu’s principles. He desperately wanted to become a Hokage in order to protect his home and those people who are close to him. He is a very firm believer in the Will of Fire according to Uchiha Madara. Because of his personality he forms a huge impact on the lives of people around him.
The ten-tailed beast [Jūbi] is the original ancient demon. All nine of the tailed beasts’ chakras are portions divided from the ten tailed beast. The Sage of the six paths defeated and sealed the demon within him, making him the first jinchūriki. While he was about to die, he divided the ten tails chakra into nine tailed beasts and he sealed its body into the moon.
Trivia: In order to guarantee that the jinchūriki wouldn't turn traitor, it has been common practice to choose the jinchūriki from the village's Kage family, such as a sibling or a spouse. The strength of the jinchūriki would then be used to protect the village and be a living display of the Kage's power. [source]