The legend of the Super Saiyan is that every 1000 years a Super Saiyan is born, but this legend does not hold true, to become a Super Saiyan the Saiyan must be enraged by anger, for example Goku became a Super Saiyan when his best friend Krillen was killed by Frieza. In the first form of SSJ the Saiyans hair becomes blonde and his eyes become green. The second form is when the Saiyan is even more enraged if he's losing a battle or someone close to him has been killed, in this form the Saiyans hair turns Gold and its get longer, his eyes also become green. The third SSJ form is when the Saiyan is even more enraged by something and his eyes become permanently green and his hair become 4 feet tall, the Saiyan also gets bigger. The fourth and finaly formation is when the Saiyan doesn't know what to do with his anger and he becomes SSJ4, in this formation the Saiyan has a red coat around his body and his eyes become red, and his hair becomes black, he is so strong that he could blow up the solar system in a flash, the saiyan also grows several feet taller. The downside to this formation is that the Saiyan can only be in this form for about 10 minute