A giant planetoid looks like it's going to hit the earth, yet explodes just before it makes impact. The inhabitants of the planet, a group of space-pirates, land on the Earth in their little ship to terraform it and use it as a new home base. They are a bunch of horned, sun-sensitive oddities led by Lord Slug--a strangely familiar green alien. Slug learns of the Dragonballs by reading Bulma's mind; he immediately collects them and makes his wish: restore his youth. After becoming young again, the fight begins.

Gohan and Piccolo face off against Slug's three main henchman: Dorodabo, a fat gargoyle, Angira, a Zarbon look-alike, and Medametcha, an extremely strange frog with the ability to create energy-sucking clones of himself. After a little bit of fighting, Goku steps in and kills Medametcha and Angira rather easily. Then it's Goku vs. Slug in one of the most predictable DBZ movie battles ever. Slug Trashes Goku. Goku goes "Super Saiya-jin" Goku trashes Slug. Slug proves to all that he's a Namek. Slug grows to super size and trashes Goku. Piccolo joins in and gets hurt. Ho-hum. Then more wierdness enters the story, as Piccolo tells Gohan to whistle--causing Slug to fall to his knees in pain. Goku flies through Slug's stomach, and then creates a small Genki-dama and defeats the Evil namek. The Earth returns to normal, birds sing, and Master Roshi wakes up from his nap and comments about the beautiful weather.