Piccolo's Decision

Vegeta decides to evacuate the Earth's population to the Tuffle planet, using ships and Goku's Instant Transmission, which he can use again as a Super Saiyan 4. Mr. Satan convinces the people that the Earth really is going to explode. As the last ship is leaving Earth, Goku locates the last four stragglers, but someone realizes they left their son back on the planet. Goku finds him, along with Piccolo. He loses his Super Saiyan 4 form, and can't use Instant Transmission. Piccolo gives him his energy, allowing him to make one last trip. He takes the boy back, but Piccolo lets go of him and is left on Earth. He telepathically tells Gohan that the Black Star Dragon Balls are too dangerous, and he plans to sacrifice himself so that they can never be used again. After Earth explodes, they make a wish on Namek's Dragon Balls to restore the planet.