Ten-Tails

This is the combined form of Kaguya Ōtsutsuki and the God Tree, created to reclaim the chakra inherited by her sons, Hagoromo and Hamura. It is regarded as the progenitor of chakra, and is tied to the legend of the Sage of Six Paths and the birth of shinobi. To end the beast's rampage, the Sage became the Ten-Tails' jinchūriki and later split its chakra into the nine tailed beasts to prevent it from causing further harm. Centuries later, its revival became the objective of Madara and Obito Uchiha, who both sought to become the beast's jinchūriki in order to further their objectives.

Background
Long before the founding of the hidden villages, during an era of endless wars between mankind, the God Tree, a tree revered as a deity, bore a chakra fruit once every thousand years. It was later revealed that the Ōtsutsuki planted the Ten-Tails seedling onto the earth with the intent to drain all chakra from the planet so that it could produce a chakra fruit for them to consume. Although it was forbidden to consume the God Tree's fruit, it was eaten by Princess Kaguya Ōtsutsuki, who used the power it granted her to end the wars plaguing the lands. Some time after this, Kaguya gave birth to two sons who became the first people born with chakra. Later, deciding that her children's chakra was rightfully hers, Kaguya combined with the God Tree to become an entity known as the Ten-Tails, which ravaged the land in an attempt to obtain said chakra. However, because Kaguya's true motives were not realised, it was instead believed that the God Tree itself had taken on the form of a monster in an attempt to regain the chakra that Kaguya had stolen.

In the final battle between the Ten-Tails and Kaguya's sons, Hagoromo and Hamura, they managed to defeat the beast by sealing its body into the moon, then sealed its remains and chakra within Hagoromo, making him the first jinchūriki. This act, along with many other great deeds throughout his lifetime, resulted in Hagoromo becoming revered as the "Sage of Six Paths". However, knowing that his death would unleash the Ten-Tails back into the world to continue its rampage and reclaim the chakra he had spread among humanity, Hagoromo separated the monster's chakra from its body and used his Creation of All Things Technique to create the nine tailed beasts. Hagoromo then used Chibaku Tensei to seal the Ten-Tails' husk in what would become the moon.

Unbeknownst to the brothers, Kaguya had created Black Zetsu prior to her sealing in order to facilitate her revival. To this end, it spent centuries attempting to unite the chakra of Hagoromo's sons, Indra and Asura, in order to cause one of their reincarnations to awaken the Rinnegan. Eventually, thanks to Black Zetsu's machinations, the Rinnegan would once again manifest itself in one of Hagoromo's descendants: Madara Uchiha. With his new power, Madara summoned the empty vessel of the Ten-Tails back into the world and named it the Demonic Statue of the Outer Path. Joined by Obito Uchiha, who continued his work after his death, Madara devised a means to reunite the Demonic Statue and the tailed beasts back into their original form so he could use the Ten-Tails to enact his lifelong ambition: the Eye of the Moon Plan.

Personality
According to Kurama, the Ten-Tails cannot be sensed through such means as detecting negative emotions as it has no feelings or ideals of its own. Despite this, when it sensed the presence of the tailed beasts' chakra inside Naruto Uzumaki and was reminded of Hagoromo, it reacted by gathering chakra and strengthening itself. It was believed that the Ten-Tails was an incarnation of the God Tree with the singular goal of regathering the chakra that Kaguya had stolen from it, but in actuality, it was following Kaguya's will to reclaim all chakra for herself.

Appearance
The Ten-Tails is brown in colour and titanic in size; one of its hands is larger than any of the tailed beasts. While the beast possess multiple forms, common attributes include a single eye, which takes up most of its head, and spiky protrusions growing out of its back in a shape reminiscent of a conch shell. When it was initially revived in an incomplete form, the Ten-Tails possessed a grotesque bulb-like body with long arms and clawed hands, but no visible hind legs, as well as a wide mouth with multiple rows of pointed teeth and a single spike on its chin. Dark veins similar to those of a plant ran along its body, and the endings of its tails resembled leaf buds, which unfurled as it began entering its second form.

In its next form, the Ten-Tails took on the shape of an emaciated humanoid with elongated limbs and a twisting neck. It now possessed visible legs, which it used along with its right arm to stand, as its left arm was missing from the elbow down. The beast's head was altered greatly, as its eye remained on the front of its head, it grew a single ear on the right side, and its mouth — which now contained straight teeth and bore a grin — moved to the left side, with a single triangular nostril appearing above it. Several horns formed on various parts on its head: two above each side of its face, two beneath its eye, and another below its ear.

As it transformed, the bud-like attachments on its tails detached, revealing extendable tails which ended in humanoid hands. After further maturing, the Ten-Tails' body became less emaciated, it grew a complete left arm, and it began standing on its hind legs. It later gained an even more muscular appearance and the horns on top of its head grew in size. When Hagoromo and Hamura encountered the Ten-Tails, it strongly resembled this form, albeit with a bloated appearance and additional spikes on its body. It also towered over entire mountain ranges, being comparable in size to Hagoromo Ōtsutsuki's Complete-Body Susanoo.

After becoming the Ten-Tails' jinchūriki, Obito expelled a construct of the Ten-Tails from his body, which then split open to reveal a gigantic tree, much like the original God Tree. This tree form, which completely dwarfed the Ten-Tails in size, possessed a tall, straight trunk with a single purple bud situated on top, inside of which was the Ten-Tails' eye. This tree form was initially stated to be the God Tree, but it was later referred to as the Ten-Tails.

When Kaguya Ōtsutsuki lost control over the tailed beast chakra inside her after being hit by Naruto Uzumaki's Sage Art: Super Tailed Beast Rasenshuriken, she unwillingly transformed into a non-humanoid Ten-Tails that manifested as a bloated, white, rabbit-like form, with the heads of the nine tailed beasts growing from various points on its body. This chakra-based form of the Ten-Tails retained Kaguya's Rinne Sharingan on its forehead as well as ten tails ending in hands.

Abilities
The Ten-Tails is said to be the progenitor of all that exists in the world. A god that created countries, it has the power to swallow oceans, split the land, and carry mountains. Kurama admitted that it alone wouldn't stand a chance against the Ten-Tails, and stated that the Sage of Six Paths said that its revival would result in the end of the world. The Ten-Tails cannot be sensed through traditional means as it gives off the same sensations as the natural energy circulating throughout the world. It is also capable of manipulating that natural energy. When Naruto attempted to gauge the power of the Ten-Tails using Sage Mode, he was overwhelmed by the vastness of the beast's power, which Kurama claimed was immeasurable. Gyūki stated that the Ten-Tails would be unbeatable if it was allowed to reach its final form.

Chakra and Physical Prowess
Considered to be the source of all chakra, the Ten-Tails has massive and overwhelmingly powerful reserves that are capable of bringing total despair and destruction to the world. Its potent levels also enable it to survive the death of its jinchūriki, forcing Hagoromo to divide its chakra into several portions (the nine tailed beasts) that are still considered to be immensely powerful. In subsequent forms, the beast's chakra increases significantly, enough to completely warp the shape of the Sensing Water Sphere at the Allied Shinobi Forces' headquarters into two connected spheres after reaching its second form.

Befitting its size, the Ten-Tails has immense physical strength and is deceptively fast, attacking Naruto and Killer B before either of them could react. It also easily deflected a Tailed Beast Ball with one finger, and created a shockwave strong enough to tear up the surrounding landscape with a single swipe of one tail. The beast is durable enough to withstand the backlash of its own point-blank Tailed Beast Ball; when its own along with Gyūki's detonated inside of its body, it briefly inflated before shrinking back down largely unaffected. Even wind-enhanced black flames only irritated the beast with no lasting damage, despite Amaterasu on its own being able to neutralise Gyūki. In its second form, the beast's tails effortlessly broke free from the various restraints created by the Allied Forces, and can freely expand in length and thickness in order to attack distant foes.

Ninjutsu
As the original tailed beast, the Ten-Tails can create a Tailed Beast Ball. In its initial form, the ball is fired as a continuous beam which could overwhelm Continuous Tailed Beast Balls from both Gyūki and Kurama without losing momentum. When the Ten-Tails matured into its second form, its Tailed Beast Ball took on a conical shape and gained an immense increase in range, firing speed and destructive power. By seeing across vast distances with its eye, the beast could hit targets great distances away from itself and destroy both mountain ranges and entire cities with a single shot. After further maturing, the Ten-Tails demonstrated the ability to unhinge its jaw, allowing it to unfurl a rafflesia-like appendage that functions as a cannon capable of firing massive and extremely powerful Tailed Beast Balls, capable of heavily distorting even the nigh unbreakable Four Red Yang Formation.

After amassing its chakra, the Ten-Tails' roar can stir a series of massive natural disasters. The Ten-Tails also has the ability to manipulate and alter its own body to some extent, allowing it to regrow lost limbs, purge burning flesh from its main body, and form additional hands to grab enemies navigating on its surface. To defend itself, it can spawn fission beings of many shapes and sizes, ranging from humanoid to animal-like in appearance, some of which wield weapon-like appendages on their arms.

Other Skills
In its final form, the God Tree's roots can extend and capture enemies as large as tailed beasts in order to absorb their chakra, turning humans into desiccated corpses in a matter of seconds. Its jinchūriki can shape these roots into other forms, such as giant wooden dragons. When the bud at the top of the tree blooms and the eye within is revealed, the Infinite Tsukuyomi can be activated. If the Ten-Tails is revived with only a piece of some of the tailed beasts' chakra, the bud may take up to fifteen minutes to bloom, though the process can be accelerated by absorbing more chakra. Those who are caught in the Infinite Tsukuyomi and attached to the roots of the tree are, over the course of years, gradually reduced to shells of their former selves and ultimately becoming White Zetsu.

Control
Madara and Obito could control the Ten-Tails in its first form by producing tendrils from its head, which then attached to their own necks. To properly control it in its second form, however, they had to reinforce their connection using Hashirama Senju's cells, and Madara suspected it would be impossible to control the beast in subsequent forms without becoming its jinchūriki. While connected to the beast, Obito was able to use its body as a medium to produce wooden spikes. A wielder of the Rinnegan can use the Six Paths Ten-Tails Coffin Seal to become the Ten-Tails' jinchūriki, obtaining the power of Six Paths Senjutsu and ten Truth-Seeking Balls. However, if the jinchūriki lacks sufficient mental strength to control the beast's power, they can undergo a psychological collapse, allowing the Ten-Tails to influence their actions. Extracting the nine tailed beasts' chakra from the Ten-Tails' jinchūriki does not put them in mortal danger, as the Demonic Statue of the Outer Path's powerful life force will sustain their life, though they will be left near death and rendered paralysed for several months.

Fourth Shinobi World War: Climax
Though only able to obtain fragments of Gyūki and Kurama's chakra, Obito fed the Benihisago and Kohaku no Jōhei to the Demonic Statue of the Outer Path, beginning its regeneration into the Ten-Tails. As Madara joined the fray, Naruto and Killer B attempted to destroy the Demonic Statue with a massive Tailed Beast Ball to stop the Ten-Tails from being fully revived. Though the statue's chakra vanished after the attack, the supposed victory was short lived as the Ten-Tails emerged from the settling smoke, causing Obito to declare it was the end of the world.

With the revival complete, Obito and Madara situated themselves atop the beast's head, from which two tendrils manifested and connected to the two Uchiha's necks. Not wanting to waste any time, Obito noted that he wished to cast the Infinite Tsukuyomi immediately while Madara wanted to test the beast's power first. After being attacked by the beast, Kurama and Gyūki launched a barrage of simultaneous Tailed Beast Balls at it only for the Ten-Tails to counter using one of its own. After the dust cleared, Naruto's shadow clone and Kakashi Hatake were launched above the Ten-Tails, where Kakashi released Gyūki, who then fired a point-blank range Tailed Beast Ball at the Ten-Tails' eye, only for it to flick the ball back at its creator with a single finger. The two Uchiha then attempted to decimate their opponents with a Tailed Beast Ball, but missed as a result of Obito momentarily losing control. With the battlefield now shrouded in mist and all sensory skills being jammed, the remainder of the Allied Forces arrived to assist in the battle.

The Alliance launched a barrage of techniques in order to incapacitate the Ten-Tails in an attempt to attack Obito and Madara, but failed as the Ten-Tails entered its second form and broke free of its bindings. The Uchiha then proceeded to devastate several towns as well as the Allied Force's headquarters with a series of Tailed Beast Balls. After the Uchiha strengthened their control using Hashirama's cells, Obito used the Ten-Tails' body as a medium for the Wood Release: Cutting Technique, with Neji Hyūga among those fatally wounded as a result, before the beast was restrained by Kitsuchi's Earth Release: Sandwich Technique. Ignoring Madara's warnings, Obito once again attempted to annihilate the Allied Forces with a Tailed Beast Ball at close range, but before he could fire, Killer B forced the attack down the Ten-Tails' throat using his own Tailed Beast Ball, causing the beast to collapse.

After Naruto distributed his and Kurama's combined chakra to the Allied Forces, the Ten-Tails was quickly overwhelmed and restrained by the Nara clan. With the assistance of Madara's power, the Ten-Tails was able to resist and attempted to assault the shinobi with its tails, only to be stopped by their combined efforts. The beast subsequently formed a cage around the Allied Forces with its tails, but the shinobi pressed forward undeterred and severed two of the beast's tails with Naruto's Rasenshuriken, separating Madara and Obito from its head with their subsequent attack. Now acting on its own accord and maturing even further, the Ten-Tails unleashed its Tenpenchii and decimated its surroundings. As the technique's effects dissipated, the Ten-Tails sensed the presence of seven tailed beasts within Naruto and was reminded of the Sage of Six Paths, which prompted it to gather more chakra, increasing its form once more. It opened its mouth wide, producing a flower-like structure to create a gigantic Tailed Beast Ball, which easily smashed through the Allied Forces Earth Release barriers, but was warped away by Minato Namikaze upon his arrival to the battlefield.

After the reincarnated Hokage had properly positioned themselves, they trapped the Ten-Tails within a large barrier topped with Hashirama's own restraints to further immobilise its movements. The Ten-Tails, aware that its capture was imminent, produced miniature clones to defend its main body. With the help of their respective summons, Naruto and the newly arrived Sasuke Uchiha got past the Ten-Tails' clones and, by combining their Wind Release: Ultra-Big Ball Rasenshuriken and Blaze Release: Susanoo Kagutsuchi, unleashed the Scorch Release: Halo Hurricane Jet Black Arrow Style Zero, which dealt a direct hit to the Ten-Tails. While Naruto and Sasuke argued about whether to remove the tailed beasts inside the Ten-Tails or simply let it burn, the beast separated the burning flesh from its body. Obito then emerged from another dimension heavily wounded and landed on the beast's head, prompting Madara to attempt to control him in an effort to properly resurrect himself so that he could become the beast's jinchūriki. Obito resisted this control and used the opportunity to seal the beast within himself, becoming the Ten-Tails' second jinchūriki.

Birth of the Ten-Tails' Jinchūriki
Once inside Obito's body, the Ten-Tails caused Obito to suffer a psychological breakdown and lose control over his own body, before ultimately gaining control over the beast's power and undergoing a second transformation. Later deciding to press on with his plan, Obito expelled the Ten-Tails from his body while remaining its jinchūriki and caused it to transform into a gigantic tree for the purpose of casting the Infinite Tsukuyomi. Once in this form, the tree's roots began absorbing chakra from the Allied Forces, reducing the time that the bud containing its eye would take to bloom. As Obito continued to dominate the battle, waiting for the blooming of the tree's bud to be completed, the senjutsu-enhanced teamwork of Naruto and Sasuke was able to land a critical hit on Obito. This allowed Naruto, Gaara, and Killer B to latch onto the tailed beast chakra within him using their own, and with the combined efforts of the entire Allied Forces, the tailed beasts were freed from Obito, halting the tree's development.

Later, after Madara once again sealed the nine tailed beasts within the Demonic Statue, the Ten-Tails revived once again. Shortly thereafter, Madara summoned the beast and sealed it within himself, making him its newest jinchūriki. When Naruto used the Sage Art: Lava Release Rasenshuriken to cut the tree left behind by Obito in half, Madara was told to absorb the falling tree, interpreting the voice in his head as the God Tree's desire to unite everything into one being.

Kaguya Ōtsutsuki Strikes
Once Madara had completed the Eye of the Moon Plan, he was promptly betrayed by Black Zetsu, who proceeded to use Madara as a medium to absorb enormous amounts of chakra from the victims of the Infinite Tsukuyomi, thereby completing the revival of Kaguya. During Team Kakashi's subsequent battle with Kaguya, Naruto was able to hit her with nine Rasenshuriken, each containing the chakra of one tailed beast. Resonating with said chakra, the tailed beast chakra within Kaguya's body grew unstable, causing her to unwillingly transform into a rabbit-like incarnation of the Ten-Tails. However, as she was within her core dimension, Kaguya was able to continue siphoning chakra out of the Infinite Tsukuyomi's victims and quickly returned to her original form. At the battle's conclusion, Kaguya was sealed once more by the combined efforts of Naruto and Sasuke, causing her to transform back into the Ten-Tails and ultimately the Demonic Statue as the tailed beasts and Madara were expelled from her body.

Versus Momoshiki Arc
Fifteen years after the Fourth Shinobi World War, Momoshiki Ōtsutsuki acquired a portion of Gyūki's chakra, which he used to re-create the God Tree in another world. Shortly after its manifestation, it was destroyed by Momoshiki and Kinshiki Ōtsutsuki during their fight against the Five Kage.

Video Games
Although it is not a selectable character, Obito summons the Ten-Tails in its second form as his awakening in Naruto Shippūden: Ultimate Ninja Storm Revolution.

Trivia

 * Deidarabotchi, also known as, was a yōkai of titanic proportions in Japanese mythology. Kurama's explanation of how powerful the Ten-Tails is reflects Daidarabotchi's role in the formation of Japan's wilderness, such as the two peaks of Mount Tsukuba, according to Japanese myth.
 * The name "Datara" may refer to, a one-eyed, one-legged blacksmith said to live deep in the mountains of Kumano. Myths vary on his nature as a yōkai or the fallen deity Ameno-me-Hitotsu. Either way, the legends say of Ippon-datara's ability to forge living things from metal that makes another reference to the Ten-Tails as the progenitor of the world.
 * The Ten-Tails' Rinne Sharingan has been depicted with varying numbers of tomoe on different occasions. When first shown as a silhouette, its eye contained nine, but it was then consistently depicted with only six tomoe after its revival. The eye contained in the bud of the tree produced by Obito was once again shown to contain nine tomoe. During its battle with Hagoromo and Hamura, its eye was depicted with four rows of tomoe, indicating it contained at least twelve.
 * In its anime début, the Ten-Tails' Rinne Sharingan was depicted as a Rinnegan.
 * The mature humanoid form of the Ten-Tails' head has three primary features: an eye, an ear and a mouth. This is possibly a reference to the maxim: "see no evil, hear no evil, speak no evil".
 * The twin rocks Hagoromo and Hamura are seen fighting the Ten-Tails on in Hagoromo's flashback are a reference to the Meoto Iwa, a pair of stones off the coast of Japan that are considered sacred in Shintō. They are bound by and represent the union of the Japanese Kami, Izanagi and Izanami. In the real world, the two rocks are located near the Grand Shrine of Ise, the most important location in Shintō.