Gyūki and the tailed beasts first came into being in the waning days of Hagoromo Ōtsutsuki, who used his Creation of All Things Technique to divide the Ten-Tails' chakra into nine separate bodies and giving each a name. Gyūki is characterised as a tough and serious individual and often speaks in a somewhat rude dialect. It can also be kind to others, especially if they're in need. It can produce Chakra-based Ink in combat.