Son Gokū (True-Clown-Prince)

Son Gokū (孫悟空, Son Gokū), more commonly known as the Four-Tails (四尾, Yonbi)

Background
Son Gokū first came into being in the waning days of the Sage of the Six Paths' life in order to prevent the Ten-Tails' resurgence, the Sage split up its chakra and used his ability known as Creation of All Things (万物創造, Banbutsu Sōzō) to create nine separate constructs of living chakra, which would become known as the tailed beasts. Some time after being created, the Sage sat down with all the young tailed beasts and told them that they would always be together even when separated, and that one day they would become one entity again with different names as well as forms than they did then when the time came for them to understand what true power was.

Son Gokū eventually fell into the possession of Iwagakure and was sealed into Rōshi over forty years before the Fourth Shinobi World War, who later left Iwagakure in a journey to gain a better understanding and control of the tailed beast.

Appearance
Son Gokū has yellow irides, white pupils, red fur and green skin. He primarily resembles a monkey, but has the build of a gorilla. It also has horns on its forehead, similar to the Third Tsuchikage's yellow jacket, as well as elongated canine teeth and spike-like protrusions on the four of its tails. Its long canines appear to be broken and are darker at the end. In its mouth it has a big, round opening, from where it spits lava, and it doesn't seem to have a tongue. The fur on its chin and on the top of its back resemble Rōshi's beard and hairstyle. During the last remaining days of the Sage of the Six Paths, Son was much smaller and had smaller teeth.