Abilities
The Four-Tails has the ability to simultaneously use the earth and fire natures, to spit lava from its mouth; something that hasn't been seen outside the realm of kekkei genkai. Since it is a tailed beast, it is able to use the Tailed Beast Ball. Four-Tails is also shown to be very strong as it was able to lift and toss the Eight-Tails.
As the Four-Tails' jinchūriki, Rōshi could borrow its ability to create and use lava.
According to Tobi, the Four-Tails first came into being in the waning days of the Sage of the Six Paths' life; to prevent the Ten-Tails' resurgence, the Sage split up its chakra and used his Creation of All Things ability to create nine separate, monstrous constructs of living chakra, which would become known as the tailed beasts. The Four-Tails eventually fell into the possession of Iwagakure and was sealed into Rōshi at a young age.
