"Ape Levels"
When a saiyan's eyes get a glimpse of a full moon, things get complicated. They will turn into this giant ape called Oozaru. It can reach heights of over 45 feet and is very powerful. In fact it is more powerful than SSJ1 and SSJ2. As long as a saiyan retains his tail he can transform into this form. Many saiyans have transformed into this including Goku, Gohan, and Vegeta. This form was used to take over planets by the orders of Frieza.
Much controversy surrounds what kind of transformation this really is. Once thought of as SSJ4 it is really a more powerful level of a saiyan after his Oozaru state. It has no real name and that is why it was called SSJ4. When in the Oozaru state, a saiyan must harness his energy to the point when he can't contain it and becomes this. Once in this state, the saiyan grows red fur on his upper body, regrows his tail, gets black hair, and reddish eyes. His power level in this form is much more powerful than SSJ3 and Oozaru. This form is so powerful that it can only retain its form for 10 minutes and then returns to a regular saiyan. A saiyan is the next best thing to a god in this form. Only Goku and Vegeta have reached this level.
If a saiyan can harness his power enough, he'll transform into the Golden Oozaru. This is more powerful than any other saiyan level. It is just like the regular Oozaru except it grows yellow hair, gets larger with more muscles, wears saiyan armor, and has a heartshattering power increase. It is said that Goku is the only saiyan to transform into this late in the GT series.
