Son Gokū

Son Gokū is a red-furred and green-skinned monkey, with a body-build of a gorilla. It has eyes with yellow irises and white pupils, spike-like protrusions along the length of its tails, elongated blunt fangs, and two long horns curving upwards on its forehead like a crown (both its fangs and horns are dark-tipped). In its mouth, Son doesn't have a tongue, but has an opening that is shaped like a dome volcano. During the last remaining days of the Sage of Six Paths, Son was much smaller and leaner with smaller fangs.

Son Gokū 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. Some time after being created, the Sage explained to the young tailed beasts that a link existed between them despite their separation. He also foretold of a day when they would be brought together again - though not as they were - and that at that time someone would emerge to show them what true power is. In the anime, before his death, Hagoromo sent Son to live in a temple built for the purpose of protecting it in a desolate rocky region that would later become part of the Land of Earth. Eventually, Son moved on to live in a new location known as the Water Screen Cave, reigning over the monkeys that resided there. During the First Shinobi World War, Hashirama Senju captured eight of the tailed beasts and sold Son and Kokuō to Iwagakure at the Five Kage Summit, as a sign of friendship and to ensure a balance of power amongst their new villages. The tailed beast would end up being sealed within Rōshi decades later who left his village in a journey to gain a better understanding and control of the tailed beast.