Saiyans

Saiyans:::....

Saiyan form 1
Saiyans are a powerful race. In appearance they look similar to humans, but they are stronger than humans. A useful quality that saiyans have is that after each fight their strength increases. Saiyans look very similar to humans. All pure saiyans have black eyes, and black hair. Saiyans also have a brown tail (similar to that of a monkeys).

Super Saiyan form
Super Saiyans are the the next level of Saiyans. In this stage the Saiyan becomes stronger and faster. It is usually trigerred by something emotional. Hair turns gold, and grows slightly. Speed increases and the Saiyan becomes more muscular. His eyes turn green. Goku was the to reach Super Saiyan, during the Frieza Saga, when Frieza killed Krillin.

Ultra Super Saiyan
This is the stage between Super Saiyan and Super Saiyan 2. Ultra Super Saiyan is stronger than Super Saiyan. The Saiyan becomes a great deal more muscular. Because of this increase in muscle mass, the Saiyan becomes slower, putting him at a disadvantage. Future Trunks was the first to reach this level.

Super Saiyan 2
Super Saiyan 2 is the stage after Super Saiyan. Hair grows longer. More muscular than SSJ. Unlike Ultra Super Saiyan, this form is both strong and fast, making the Saiyan a very powerful warrior. Gohan was the first Saiyan to reach this level, in the Cell saga.

Super Saiyan 3
This is the next stage after Super Saiyan 2. The Saiyans hair grows much longer, down to to the waist. Eyebrows disappear, and the Saiyan becomes more muscular. This form is very powerful. The Saiyan is much stronger and faster than Super Saiyan Level 2. This is the highest level reached in DragonballZ. Goku and Gotenks are the only two Saiyans to have reached this level.

Super Saiyan 4
This is the fourth level a Saiyan can reach. Hair turns black again, and it is slightly longer than normal. Red fur grows all over the body except the chest. The tail grows back if it was ever lost. The Saiyan's muscle mass increases again. Super Saiyan 4 is extremely strong and fast. Only Goku and Vegeta reach this stage (DragonballGT). This stage makes the Saiyan basically a perfect warrior.