From Dragon Ball Wiki, the ''Dragon Ball'' encyclopedia
The Electric Slime is a restraining technique used by Rage Shen Long. Rage can generate and control the massive amount of electricity-draining pink ooze. The Electric Slime can apparently replicate itself by absorbing enough electricity, but water will cause it to short out and even explode in large enough masses. Rage also used it to become much larger and stronger, which is known as the Electric Slime Body Build.
Rage used his Electric Slime against Son Goku and Pan, who had confronted him in order to restore Earth and the Dragon Balls. Goku and Pan could not escape from the sticky slime as it stopped them in their tracks. The sticky substance electrocuted them and seemingly killed them. However, they recovered from the attack with little harm and much to the shock of Rage. Rage then used it to make himself much larger, thus forcing Goku to turn Super Saiyan 4. The slime was soon defeated when it rained on the battlefield, making Rage's body short-circuit.