In the film this form was originally labeled as the true Super Saiyan form, but later re-labeled as Giji or "Pseudo" Super Saiyan after the actual Super Saiyan form was introduced in the Dragon Ball manga.
In this form, Goku's irises and pupils are no longer visible. His body bulks up a little, his hair almost straightens, 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 (due to the reflection of the yellow aura on his black hair, his hair is not actually red). He gains a yellowish surge of aura.
During the battle against Lord Slug, Goku's strength began to quickly debilitate. Having no more options, Goku's anger surged, causing him to gain a massive power increase, manifesting his Super Saiyan powers and making him become like a Super Saiyan, enough to quickly overwhelm Slug. The form faded after a while; more specifically, Goku seemed to regain his usual self when Slug ripped his arm off and regenerated it. This may suggest Goku was not in his usual state of mind, as indicated by his pupil-less eyes and his erratic attacks.
One way to put it is that the Pseudo Super Saiyan transformation occurs when a Saiyan doesn't have a strong enough mental urge to properly transform, as none of Goku's friends had actually perished, so there was no real pain of loss. It is apparent, however, that the form gives a large power increase, enough for Goku, who was being easily beaten previously by Slug, to now quickly overwhelm him.
- Broly also displays a similar form in Paragus' first flashback sequence during the movie Dragon Ball Z: Broly - The Legendary Super Saiyan, in which a teenage Broly is running amok, destroying planets unrestrained. The form's hair stands up on end like Broly's Super Saiyan form and has the same reddish tint to the hair as Goku's False Super Saiyan form; however, his eyes retain their pupils. Also, Broly exhibited a similar transformation when escaping the destruction of Planet Vegeta due to his eyes going blank.
- Vegeta's Saiyan Soul power up that he uses against both Goku and Frieza in the anime, strongly resembles the Pseudo Super Saiyan form. During these instances, he is surrounded by a golden aura, his pupils disappear completely, his hair reflects the gold from his aura, and his ki skyrockets to the point of extreme environmental effects.
- There is actually a glitch in Dragon Ball Xenoverse 2 that makes the Future Warrior look like a Pseudo Super Saiyan. If the Warrior is equipped with the skill Hell Flash and uses it while using any Super Saiyan form, they will automatically revert to their base form but with the Super Saiyan aura remaining, making them look similar to a Pseudo Super Saiyan.