One of the recurring hallmarks in Akira Toriyama's Dragon Ball franchise is for its characters to undergo escalating physical transformations to attain higher levels of combat power. Dragon Ball Z introduced the concept of its Saiyan characters -- beings from an extraterrestrial warrior race that had arrived on Earth -- being able to charge up their power and transform into Super Saiyans, marked with a golden aura and hair as they achieved a significant power boost.
Over the course of DBZ, the Saiyans unlocked Super Saiyan 2 and Super Saiyan 3 transformations to further augment their strength and abilities but, while Super Saiyan 2 appeared as a natural extension of the preceding form, Super Saiyan 3 remains one of the most unusual Saiyan transformations in the entire franchise.
Goku first unveiled the Super Saiyan 3 transformation during his first encounter with Majin Buu to buy Trunks enough time to recover the Dragon Radar. Despite knowing the advanced form would consume much of his time granted on Earth as he was still technically dead, Goku proceeded to show off the new transformation anyway, using it to hold Buu at bay and give the villain his first legitimate challenge since his reawakening by the evil Babidi. Goku would use the form sparingly during his subsequent rematches against Buu as the antagonist took on progressively more powerful forms, with the composite warrior Gotenks similarly able to achieve the Super Saiyan 3 transformation after Trunks and Goten merged together through the Fusion Dance.
With its shock of long golden hair extending to the user's waist and pronounced brow visibly eliminating their eyebrows, a Super Saiyan 3 is barely recognizable from the user's natural appearance. Additionally, the transformation gives its user a noticeably increased muscle mass, the biggest of any Saiyan transformation to date, with Goku and Gotenks both appearing visibly larger when taking on the form. And this drastic change in appearance may be a result of the transformation's afterlife origins.
Goku unlocked the form while training for seven years in the afterlife where his body became more able to handle the strain. After being resurrected, Goku found that the transformation took a greater physical toll on him, burning through energy at an accelerated pace. Given its unusual origins, Vegeta and Gohan were unable to achieve the transformation for themselves, with Gotenks only able to make the transformation after Goku demonstrated how to attain it. The fused warrior used his vast energy reserves -- thanks to the fusion -- to follow Goku's example.
Due to the heightened energy consumption, Goku uses Super Saiyan 3 sparingly, favoring Super Saiyan God and Super Saiyan Blue in Dragon Ball Super as the godly transformations consume energy at a slower rate. And, in addition to the reduced physical strain, Super Saiyan God was visibly less aggressive than Super Saiyan 3, which appeared to require a significant amount of rage to achieve, with Goku having to work up his anger for a prolonged period of time just to transform.
With its striking change to its users' physical appearance, Super Saiyan 3 is a transformation only seen briefly since its debut towards the end of Dragon Ball Z. Goku would rely on different Super Saiyan transformations in subsequent anime series, citing a decreased rate of energy consumption as well as an increase in power. As a form discovered in the afterlife, it remains one of the most enigmatic Super Saiyan transformations to date, with only Goku and Gotenks canonically able to achieve it while other warriors would bypass it entirely.
