The 10x Kamehameha is a beam attack technique in the Dragon Ball franchise. It made its debut in "The Tuffle Gorilla Attacks!", the 36th episode of Dragon Ball GT, which premiered on February 12, 1997. The technique is a more powerful adaptation of the Super Kamehameha, which Goku uses in his Super Saiyan 4 transformation.
The 10x Kamehameha was first developed by Goku while battling a Baby-possessed Vegeta. Despite being at Super Saiyan 4, Goku begins to struggle after Super Baby Vegeta transforms into a Golden Great Ape. Midway into their fight, Goku rises into the air, and unleashes the attack for the first time.
Despite its astounding power, the attack does little damage to Baby. However, shortly after the delayed effect of the technique kicks in and the tyrant is paralyzed temporarily, sending him plummeting to the ground (this side-effect is completely absent from video game incarnations of the technique, fundamentally making the 10x Kamehameha no different from a normal beam attack). Later during the fight, Golden Great Ape Baby Vegeta launches a Revenge Death Ball Final at Goku, who retaliates by absorbing its massive power and returning it in the form of a powerful 10x Kamehameha at Baby, severely damaging the tyrant. Goku later uses the 10x Kamehameha to send Baby's spaceship hurdling into the Sun during his attempt to escape.
The technique is next used by Goku against Super 17, when in response its energy is merely absorbed by the android. Later during his battle with Syn Shenron, Goku, again in his Super Saiyan 4 transformation, launches a 10x Kamehameha head-on, which evidently has no effect on the Shadow Dragon. In the ensuing battle with Syn Shenron, who by now has absorbed the Dragon Balls and assumed his Omega Shenron transformation, Goku retaliates with a combination of the 10x Kamehameha and Dragon Fist techniques, which the Shadow Dragon survives by regenerating.
During its first use in the Baby Saga, the 10x Kamehameha is whitish-blue in appearance, much like the standard Kamehameha (an earlier technique which the 10x Kamehameha resembles in most respects), however, later uses see its appearance permanently altered so that it emits a crimson aura instead.