According to Madara Uchiha, the Five-Tails came into being in the waning days of the Sage of the Six Paths' life; to prevent its resurgence, the Sage split up the chakra of the Ten-Tailed Beast into nine separate, monstrous constructs of living chakra, which would become known as the tailed beasts. The Five-Tails eventually fell into the possession of Iwagakure and was sealed into Han.
The Five-Tails is often portrayed as the fastest of the tailed beasts, and sometimes the most paranoid. It is said to be ’always on the run’.
- According to Kishimoto's words from the second Naruto artbook, he tried to do a mix of a dolphin and a horse.