The 10x Kamehameha is a higher-powered version of the Super Kamehameha. It made its debut in Dragon Ball GT and has since made appearances in several video games spun off by the series, such as Final Bout.
The technique was first developed by Goku while battling Baby. Despite being Super Saiyan 4, Goku begins to struggle after Baby 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 massive 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. Goku later uses the 10x Kamehameha to send Baby's spaceship hurdling into the sun during his attempt to escape.
The attack is next used by Goku against Super 17, when in response its energy is merely absorbed by the android.