Super Saiya-jin Level 1
This stage was first reached by Goku in movie #2 as he fought Lord Slug. He
didn't appear to be a Super Saiyan then, since his hair had a black tinge to it.
Officially, Goku went SSJ1 for the first time in the Freeza Saga, after Freeza
killed Krillin. Physical description: Increased muscle mass, and long blond hair
that stands on end. Occasionally accompanied by a yellow wave, or lightning.
Super Saiya-jin Level 2
In movie 9, Gohan was told by Goku to go SSJ2, which he did in order to kill
Boujack and the rest of his crew. This level is much more powerful than SSJ1.
SSJ1 was used quite frequently in movies 4 through 9, but SSJ2 had more
immediate results. SSJ1 proved inefficient in stopping Boujack's crew, and when
Gohan reached SSJ2, he easily overpowered the aliens. Physical description:
Greater muscle mass than SSJ1, and a few more inches of blond hair. Occasionally
accompanied by zapping silver lightning.
Super Saiya-jin Level 3
Goku first achieved this level during a fight with Majin Buu. This is the most
powerful level of Super Saiyan. Majin Buu could overpower SSJ3, but this level
did destroy Fat Janenba in movie #12. SSJ3 was also used in Dragon Ball GT, but
Goku couldn't hold it due to his little body's lack of strength. Physical
Description: Goku's physical appearance is more lean and menacing looking, with
about 4 and half feet of flowing blond hair and a larger muscle mass.
*Note* Only Goku and Gotenks have achieved this level. No other Saiyan's have
ever reached it.
Super Saiya-Jin Level 4
There is question as to whether or not this is an SSJ level, seeing as how Goku
doesn't have blonde hair when he reaches this level. However, he does have
increased muscle mass. This is also the only stage with a tail. In SSJ4, Goku is
almost god-like, and he can use "Times 10 Kamehame-ha." Physical description:
Although Goku was wished by the Dragon Balls to become a child again, in SSJ4
form, he has his normal adult body with a bit more muscle mass. His upper torso
is covered in red fur, his hair is black, and his eyes are red rimmed.
When a Saiyan stares at a full moon, he/she will change into a 20-foot tall,
monsterous monkey called a Were-monkey (Oozaru, in Japanese, translates to "Big
Monkey"). This is possibly the most powerful level under SSJ3. All Saiyan
(excluding Goku and Gohan) will be able to control themselves during this stage
(although in Dragonball GT, it is implied that Vegeta couldn't control himself
in Oozaru form, but Bedi could.) It doesn't matter which full moon they look at
(in Dragonball GT, Goku turned Oozaru by looking at the full Earth. And Vegeta
had the ability to create a pocket-sized full moon when he first arrived on
Earth to fight Goku and Gohan that made him turn into the Were-Monkey.)
*Note* A Saiyan must have a tail to be able to turn Oozaru. If the tail is cut
off, they revert to normal. If the tail is pulled out by the roots, the Saiyan
will never be able to turn Oozaru again.