Something that happens to the Saiyajins in Dragonball Z after enough training and getting pissed off. Greatly increases their strength and power. After a while, they return to normal (or what passes for normal for a Saiyajin), but they can switch back whenever they want.
Origionally there was only supposed to be one Super Saiyajin (the legendary Super Saiyajin), but eventually all the Saiyajins on the show can do it.
There are 4 levels of Super Saiyajin:
- SSJ Level 1
Their hair flips up into a very spikey hairdo (no matter what the length/style it was
before) and turns a bright blonde (again, ignoring whatever color it was before).
The best way to discribe the power level of SSJ Level 1 is through an analogy. A first level Super Saiyajin is to a normal Saiyajin as a
Saiyajin is to a normal human.
There are many ways to advance to SSJ 1. Son Goku did it through his extensive training and the anger at the death of his friend, Krillin.
Vegeta goes SSJ 1 when he travels to a distant planet to train and a meteor shower hits. He gets pissed off about the fact that a huge comet is
going to destroy his spaceship that he goes SSJ 1 and destroys it.
- SSJ Level 2
When a Saiyajin becomes this level of Super Saiyajin, their hair stands up straighter and turns more or less the color of white gold. The
power jump from SSJ Level 1 to level 2 is proportionally similar to the jump from normal Saiyajin to SSJ Level 1.
I'm not sure how the transition between levels 1 and 2 work because I haven't seen those episodes of Dragonball Z yet. I'm pretty sure Son
Goku, Vegeta, and Gohan all become this level
- SSJ Level 3
Their hair keeps the spikes and color of SSJ Level 2, but it now extends down their back past their waist.
Son Goku reaches this level during the Buu Saga, which catches the attention of basically everyone in the DBZ universe. The Goten/Trunks
fusion also reaches this level. (Thanks Shadus for the reminder.)
- SSJ Monkey
After level three, they can go Super Saiyajin in their ape form. Big, Yellow, and Ugly.
Looks exactly like the normal Saiyajin ape (when they see a full moon), except covered in blonde hair instead of brown. Very powerful, and perhaps not the brightest thing around. Not something I want in my town.
- SSJ Level 4
The highest form of Super Saiyajin in Dragonball Z and Dragonball GT. The Saiyajin's appearance returns to almost normal, but they are
covered in red fur. Very powerful. Pretty much Godlike.
To my knowledge, only Son Goku and Vegeta ever reach this level. However, I haven't seen the whole series yet.