Giji Sūpā Saiya-jin
From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
In this form, Goku's irises and pupils are no longer visible, mostly in turn to the power and bleak rage. His body bulks up a little, his hair straightens like that of a Super Saiyan, his skin color also appears to have a yellow hue to it, but there is no considerable change in feature other than a red tint to his hair. He gains a yellowish surge of aura, somewhat, but not quite, resembling that of a normal Super Saiyan's aura. In turn, the form somewhat resembles a glorified Kaio-ken form and even makes the same sound as it. Notable differences, however, exist.
Before he transformed into a Super Saiyan in his fight against Freeza, Goku had witnessed the murder of his best friend, Kuririn (as well as the fact that Kuririn was not likely to be revived with the Dragon Balls since Shen Long had already granted that wish and could not resurrect the same person twice), something that drove him over the edge. This ultimate pain was not fully present during the fight against Slugg, and Goku was not at the same battle power as when he fought against Freeza. These two reasons are most likely why Goku did not transform fully into a Super Saiyan. The Giji Sūpā Saiya-jin form was shown to be very erratic, lasting for only as long as the aura was ignited and using up much more energy to sustain than the full Super Saiyan.
The Giji Sūpā Saiya-jin form was originally labeled as the Super Saiyan form in the film, but was later relabeled as Giji Sūpā Saiya-jin in Dragon Ball: Daizenshū 7 after the actual Super Saiyan form was introduced in Dragon Ball Z.
Goku's strength began to quickly drop in his battle against Slug in Dragon Ball Z: Lord Slug. Having no more options, Goku's anger surged and caused him to gain a massive power increase, enough to quickly overwhelm Slug. After a quick sequence of thrashing Slug around, however, Goku's Giji Sūpā Saiya-jin power quickly faded.
One way to put it is that the Giji Sūpā Saiya-jin transformation occurs when a Saiyan has the required physical power, but lacks the mental need to transform into a Super Saiyan. It is apparent, however, that the form gives a large power increase, enough for Goku, who was being easily beaten by Slug, to quickly overwhelm him.
- At first, North Kaio believes this transformation is the Super Saiyan transformation.
- A popular misconception among fans is that Future Trunks once became a Giji Sūpā Saiya-jin due to the similar appearance of the form he took in Dragon Ball Z: The History of Trunks. Daizenshū 7, however, only lists Goku as a user of this transformation even though both Son Gohan and Future Trunks display similar characteristics of the form in the anime.
- A similar misconception involves Goku's form in "Warriors of the Dead". In this case, however, it was a last-minute decision to keep Goku's Super Saiyan powers hidden from Pikkon rather than a simple coincidence, thus his hair was digitally altered from gold to black and his eyes from green to black. (In the original Japanese promo for the episode, Goku's hair turns gold and eyes turn green.) The aura was oddly untouched.