Super Saiyan 2 (超サイヤ人ツー, Sūpā Saiya-jin Tsū) is the direct successor to the first Super Saiyan transformation. It is very similar to the original form in appearance and attainment, however the power output is far greater, as speed, strength, and energy output all drastically increase. Gohan was the first person to attain the form while fighting against Cell in the Cell Games.
In order to achieve this transformation, the Saiyan must first gain a huge amount of energy (usually by training), far beyond that required for the first Super Saiyan form. Once enough energy is acquired, the Saiyan must experience a powerful emotional upheaval, much like the Super Saiyan transformation, but to a greater extent. Because of the intense emotion required to initiate the transformation, any mastery of the Full-Power Super Saiyan state, and mental stability attained therein, is negated, and the naturally remorseless nature of the Saiyan race is magnified, requiring them to remaster the personality changes. Even the gentle, polite Gohan becomes a hotheaded, merciless fighter after transforming, opting to torture Cell rather than kill him despite Goku's pleas. The power output emitted by this form is greatly increased as well, as it doubles the strength of the regular Super Saiyan transformation, as stated by the Super Perfect Guide.
The golden hair brought on by the original transformation becomes longer and rigid; any hair that hung loose in the Super Saiyan transformation (in the case of Goku or Gohan, because Vegeta lacks any bangs in front of his face, as does Gotenks) is now raised. Increased energy radiation causes the aura to take on a jagged, fierce flame-like appearance rather than smooth or flowing. Because the energy output and radiation is higher than that of any Super Saiyan, the aura pulses at a higher frequency, like the type 2 aura, at least in the manga. Muscle mass is barely increased, but energy output is multiplied manyfold; such that greater amounts of the Saiyan's increased energy capacity can be used at once for much more powerful energy attacks, and even speed is augmented incredibly by the boost, unlike the Ascended and Ultra Super Saiyan states which cause the muscle mass to swell and thus impede the user. Another notable feature of the form featured in almost all Dragon Ball Z games and some scenes of the show as well as pictures from the manga, is the electrical aura, many electrical sparks (normally blue, gold in Dragon Ball Z: Budokai 3) that constantly surround the body — especially when charging up. However, they aren't always present (especially in the anime; Gohan and Vegeta aren't the only ones who lack the trait completely in some episodes), and some fans sometimes mistake a charging Super Saiyan for a Super Saiyan 2 due to the lightning sparks, such as Vegito; in the manga, they never reappear in his aura after his transformation, nor are they ever shown on any other first-level Super Saiyan.