Shukaku

, more commonly known as the, is one of the nine / tailed beasts. It was last sealed within Gaara of Sunagakure, after being sealed in two other jinchūriki before him.

Background
Shukaku first came into being in the waning days of the Sage of the Six Paths, who used his Creation of All Things ability to separate the Ten-Tails' chakra from its body and divide it into nine separate constructs that would come to be known as tailed beasts in order to ensure that it would never resurface after his death. Some time after being created, the Sage sat down with all the young tailed beasts and told them that they would always be together, even when separated, and that one day they would become one entity again with different names and forms than they did. Then, when the time came, they would know what true power is.

Shukaku would eventually be captured and kept by Sunagakure, to which the First Kazekage, who was invited along with other first Kage by Hashirama Senju into the first summit, attempted to use his possession of the tanuki as leverage to gain wealth for his nation, as opposed to gaining another tailed beast.

Shukaku's first jinchūriki was a Suna priest named Bunpuku, who was locked away in a dungeon with the giant tea kettle, and was kept under constant guard. Over time, the citizens of Sunagakure came to believe that Shukaku itself was a of a corrupted priest sealed inside a tea kettle. Despite the animosity the village showed for Shukaku and its host, the elderly priest held no ill-will towards the tanuki nor the villagers, viewing it as as an equal and was content as long as Shukaku hadn't forgotten his name. Shukaku eventually came to appreciate Bunpuku and would later remember the words he imparted to it: that someday someone would appear in the world to teach it about the heart and acceptance. Shukaku had another jinchūriki who inspired the Third Kazekage to create his Iron Sand fighting style. Shukaku was eventually removed from their bodies, resulting in their respective deaths.

When Karura became pregnant with Gaara, her husband, the Fourth Kazekage, had Chiyo seal Shukaku into Gaara while he was still in the womb because, out of his three children, Gaara was the only one compatible with the tailed beast. Before Karura died after giving birth, she passionately told her son that she would protect him, and, according to her husband, her love seeped into the sand and was noted to form his automatic defence. However, Gaara couldn't properly control Shukaku's powers, killing or injuring several of Suna's shinobi and citizens by accident. Shukaku would even cite its hatred toward humans, warning Gaara not to sleep too long if he didn't want to give Shukaku an opening. Deemed a failure, the Fourth Kazekage chose to test his son one last time, ordering Yashamaru to assassinate him and also tell him that his mother never loved him, and that she was used as a human sacrifice for the sealing process. Gaara failed the test, fully releasing the rampaging Shukaku, to which the Fourth eventually used his Gold Dust to subdue the tanuki.

Personality
Shukaku is characterised as a wild and short-tempered individual, and often speaks in a bombastic and incoherent manner, giving it the demeanour of a drunken madman, to which Gamakichi describes it as "pretty funky". Shukaku also expresses pride as it uses when referring to itself, and holds great confidence in its own abilities, especially its absolute defence. According to Gaara, prior to its introduction, Shukaku relishes the opportunity to kill anyone in sight, even more so during a full moon. Like all tailed beasts, Shukaku has shown a strong desire to preserve its own life, granting its jinchūriki the power to control sand as well as allowing them to transform into it in a state of need and blood-lust.

Shukaku harbours a bitter grudge towards Kurama due to the latter's beliefs that the tailed beasts' strength is measured by the number of tails and thus Kurama views Shukaku as the weakest. Due to this, Shukaku will find any opportunity to surpass its arrogant rival. Its hatred towards humans led it to spark fear in Gaara, reminding him that if he goes into a deep sleep, the tanuki would possess his body and murder all humans, resulting in Gaara's developing insomnia. Shukaku had a similar attitude towards Bunpuku, but its jinchūriki learned to live with it and eventually, Shukaku complimented him by comparing him to the Sage of the Six Paths. During the Fourth Shinobi World War, Shukaku eventually saw Gaara in a similar light, being reminded of Bunpuku.

Appearance
Shukaku is a sandy-brown coloured tanuki, with black (dark blue in the anime) cursed seal markings all over its face, body, and tail. It has a jagged, concave mouth and the sclerae of its eyes are black, with yellow irides and pupils that each takes the shape of a black four-pointed star with four black dots around it. During the last days of the Sage of the Six Paths, Shukaku in its youth looked the basically same as it does presently, only much smaller.

Abilities
As a tailed beast, Shukaku possesses a large quantity of chakra and can perform the Tailed Beast Ball. As a precaution to if its jinchūriki lost control and fully transformed into Shukaku inside of Suna, the villagers were to either evacuate beforehand or seek shelter due to the risk of mass casualty from its rampage. Shukaku has the ability to control its jinchūriki whenever they sleep, which leads to its host to develop insomnia. Shukaku has great physical strength while using its tail, as seen when overlapping it with the other tailed beasts to shatter and even obliterate a senjutsu-enhanced complete Susanoo.

Sand Manipulation
Shukaku's most notable ability is its sand manipulation, using it as an effective weapon and shield. Since its whole body is completely made of sand, the tanuki can ignore most damage that would otherwise be detrimental, as shown when it had one of its arms chopped off by Gamabunta and was still able to keep on fighting. Taking pride in its motto of absolute defence, Shukaku's sand is durable enough to block a senjutsu-enhanced Susanoo sword with ease. It is capable of performing fūinjutsu by using its natural cursed seal markings across its own sand body, which gives off a magnetic field to bind its targets. One of its techniques, the Desert Layered Imperial Funeral Seal, is strong enough to temporarily restrain and withstand powerful techniques, like the Susanoo.

Nature Transformation
Shukaku can use the Wind Release, Earth Release, and Magnet Release nature transformations. It could rapid fire Wind Release: Drilling Air Bullets with such force to level entire forests. Likewise, it can combine its wind abilities with Gaara's sand in order to produce a mass of fast-moving sand bullets. Shukaku's Magnet Release is used through the markings of its cursed seals and could be infused into the Rasengan to create Sage Art: Magnet Release Rasengan.

Konoha Crush
During the Konoha Crush, Gaara partially transformed into Shukaku during his fight with Sasuke Uchiha, lashing out with the tailed beast's arm after being injured for the first time and terrifying Sasuke with a glimpse of its eye. Gaara later transformed into his full Shukaku form during his fight with Naruto Uzumaki, who summoned Gamabunta to counteract it. When Gaara exposed himself on top of Shukaku's head and used the Feigning Sleep Technique, Shukaku took full control of its body and battled them. Shukaku's power was too much for Gamabunta to handle, resulting in both him and Naruto using the Combination Transformation to take the form of a giant fox (Kurama in the anime). Gamabunta used the form's claws and teeth to grab and restrain Shukaku, in order for Naruto to wake Gaara up with a punch, which suppressed Shukaku's power.

Kazekage Rescue Mission
During Gaara's time as the Fifth Kazekage, Deidara and Sasori from the Akatsuki were assigned to capture Shukaku. During the battle between Gaara and Deidara, Gaara manifested Shukaku's arms several times to attack the Akatsuki member. After Deidara defeated Gaara in combat and took him to Akatsuki's lair in the Land of Rivers, Shukaku was forcefully extracted from Gaara and placed within the Demonic Statue of the Outer Path. Though the extraction killed him, Gaara was resurrected through Chiyo's One's Own Life Reincarnation technique and has still retained the ability to control sand.

Birth of the Ten-Tails' Jinchūriki
Shukaku was the only tailed beast sealed within the Demonic Statue to have not been resealed into Obito Uchiha's Six Paths of Pain and as such, did not meet Naruto during his encounter with the other tailed beasts. When Naruto proceeded in his plan to pull all the beasts from Obito's body in order to halt the tree form of the Ten-Tails' flower from blooming and completing the Eye of the Moon Plan, its chakra rejected Naruto as he contained none of the tanuki's chakra. Gaara, having been bonded with Shukaku, instead took hold and began pulling the chakra himself. Through the efforts of the Kazekage, Shukaku was freed from its captivity alongside the other tailed beasts. Upon being freed, Shukaku started to recognise Naruto. Despite showing reluctance to Gaara's request for its help in sealing Madara Uchiha, Shukaku decided to do so only for the opportunity to surpass Kurama.

When Madara ran towards them and the other tailed beasts, both Shukaku and Gaara conjured numerous sand bullets and were able to restrain the Uchiha's movements. Despite them forming the Desert Layered Imperial Funeral Seal, Madara managed to escape the sand pyramid with his Susanoo. As Naruto in Tailed Beast Mode pinned Madara down with a tail, Shukaku and the other tailed beasts joined in and did the same to increase the damage, but the Uchiha survived their attacks and retreated to a safe distance. After he received his own right Rinnegan eye from a White Zetsu clone, Madara quickly summoned the Demonic Statue of the Outer Path from Obito's body, and used the Rinnegan to repel the tailed beasts.

With the tailed beasts stunned, Madara then proceeded to chain them up and prepared to seal them back into the statue. As Madara began the process on Shukaku, Gaara intervened, declaring his refusal to let Madara get his former tailed beast. Shocked at how determined Gaara was to protect Shukaku despite their negative past, the tanuki remembered Bunpuku's words of wisdom. From that, it also recalled Gaara explaining that he'd been grateful to Shukaku as it was thanks to the tanuki that Gaara had met his first friend, Naruto. As Madara launched an attack on Gaara, Shukaku quickly blocked the attack for its former jinchūriki. Despite their new-found team-work, Madara still rebuffed their efforts. Ultimately, Shukaku, along with the other tailed beasts, are all resealed within the Demonic Statue.

Later, after Madara succeeded in becoming the Ten-Tails' jinchuriki, a reformed Obito managed to steal some of Shukaku's chakra along with some of Gyūki's. Then Obito sealed the Yin half of Kurama into a dying Naruto to save his life, Obito also sealed Shukaku and Gyūki chakra portion into Naruto. Inside Naruto's subconscious, Shukaku, Gyūki and Yin Kurama found the Konoha-nin talking with the spirit of Hagoromo Ōtsutsuki. They voiced their unanimous belief to the Sage that Naruto is the child of prophecy. The other six tailed beasts chakra then manifested to join in the meeting. As Naruto fought Madara, Shukaku aided him by lending its Magnet Release chakra, allowing Naruto to use a fūinjutsu technique against Madara.

Kaguya Ōtsutsuki Strikes
Ultimately, Kaguya Ōtsutsuki who has taken control of Madara is defeated by Naruto Uzumaki and Sasuke Uchiha and sealed using the Six Paths — Chibaku Tensei technique. The beasts are all ejected from the statue and then they are all summoned back to the real world by Hagoromo and the previous Kage. After the past Kage return to the after life, the tailed beasts begin discussing their plans for the future now that they are finally free. Sasuke however makes his plans known. Desiring to kill the current Kage and seize control of the tailed beasts for his plans of revolution in the shinobi world, he quickly accomplishes the latter with his Rinnegan. With the tailed beasts subdued by his genjutsu, Sasuke then seals them away within his Chibaku Tensei. After the battle when Sasuke declared Naruto the victor, the two dispelled the Infinite Tsukuyomi and Sasuke released Shukaku along with the other tailed beasts from their prisons.

Video Games
Shukaku appears as a boss in Naruto: Ultimate Ninja Storm and Naruto: Rise of a Ninja, and a false replication of it is a boss in Naruto Shippūden: Kizuna Drive. Shukaku itself is playable as its full form in Naruto: Ultimate Ninja 3 and as an awakening for Gaara in Naruto Shippūden: Ultimate Ninja Storm Revolution, and Gaara takes on its miniature form in Naruto: Ultimate Ninja 3, 4, and 5.

Trivia

 * literally means 'protector crane'.
 * A is a popular figure in Japanese folklore and is famous for its mischievous nature and abilities to shape-shift. Tanuki are also said be rivals to the kitsune, which created an old Japanese proverb:, meaning two sly characters trying to outsmart one another. Shukaku being sealed inside a tea kettle is a reference to one Japanese tale called Bunbuku Chagama. In addition, Shukaku being claimed to be a corrupted Suna priest earlier in the series, has ties to a legend in the Kenchō-ji temple of a tanuki disguised as the shrine's priest.
 * Shukaku is the first tailed beast to have its name revealed in the series. In addition, Shukaku is the only tailed beast that hasn't been shown giving its jinchūriki the characteristic red chakra-shrouds (Version 1 or Version 2 forms). This is presumably because Shukaku appeared early in the story when Kishimoto have not yet defined the specific abilities that all the tailed beasts share.
 * When chapter 629 was first released, Shukaku's image was seen among the tailed beasts, despite not having the chance to give Naruto its chakra like the others, suggesting an error. In the tankōbon version, it was removed.

Quotes

 * (To Naruto and Gamabunta) "I'm finally out!! And here's someone that I want to kill right now!!"
 * (To Gaara)
 * "My motto is absolute defence… That is what I, Shukaku, pride myself on!"