The Six-Tails (translating for "Rokubi") is one of the ten classes of the tailed beasts.
Six-Tails uses 'ore' (オレ) when referring to itself, 'ore' being a boastful way of saying 'I'. It also speaks with a dialect which may possibly be Osakaben. Six-Tails are nervous about meeting humans, but given time, they can achieve great friendship with them.
Sometimes they can be shown to have jealously at a human who is in relation with their own jinchuriki, but later on trusts them as they can also grant them a portion of their chakra to them.
Six-Tails are the fifth strongest of the tailed beasts, so they can flex themselves through the cracked landmarks and can read through any strageries or tactics in circumstances. Six-Tails can simultaneously use three chakra natures as those can become a mixture for an advanced chakra nature. Six-Tails has a great amount of chakra and it is able to use it to create Tailed Beast Bomb.