The Ten-Tails is brown in color 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.
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 Shinju 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.
Monstrous Chakra Power: 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 jinchuriki, 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.