The Nine-Tailed Demon Fox is the tailed beast sealed within Naruto Uzumaki of Konohagakure and was previously sealed within Kushina Uzumaki and Mito Uzumaki before her.
Abilities
Being the strongest of the nine tailed beasts, the Nine-Tails is said that it can create tsunamis and flatten mountains with just a single swipe from one of its tails. With its massive supply of chakra, it can turn its roar into a powerful shock wave that can repel and destroy anything within its radius, increase its physical strength and speed, and fire Tailed Beast Balls. In the anime, it was shown to be able to create twisters and breathe fire.
During its battle with Naruto in his subconscious, it was shown that even though it had its Yin chakra sealed away, the Nine-Tails was more than powerful enough to overwhelm the Eight-Tails' attempts to restrain it (although Killer B stated that he didn't have full access to his own powers within Naruto's mind), and effortlessly block Naruto's Sage Art: Ultra-Big Ball Rasengan with its tails. Naruto also noted that it was extremely fast despite its massive size. Later, even after most of its chakra was taken by Naruto, it still had enough to create a Tailed Beast Ball many times its own size. If its jinchūriki dies (causing the Nine-Tails to die with them), the Nine-Tails will later revive.
Even though it is extremely durable, the Nine-Tails, when caught off guard, can be weakened by attacks that deals with massive physical impacts, such as Naruto's senjutsu-enhanced Wind Release: Rasenshuriken and Sage Art: Many Ultra-Big Ball Spiralling Serial Spheres. It is also susceptible to control by the Sharingan, though only Madara Uchiha and Tobi had accomplish this great feat. Sasuke Uchiha had also used his Sharingan on the Nine-Tails, but only to suppress a small amount of its chakra.
After Naruto conquered his dark side, it was revealed that the Nine-Tails also has the ability to sense negative emotions, after it inquired about the "real Naruto". Naruto also gained access to this ability after gaining control of its chakra.
