The Two-Star Dragon
Haze Shenron, the dragon of pollution has begun to contaminate everything in his path by emanating a toxic mist that poisons everyone and everything who breathes it. Goku and Pan soon find themselves overcome by the noxious fumes. With the Saiyans choking on the foul air, help must come from an unexpected source.
Aired 18/06/1997EP 49 - The Two-Star Dragon
Dragon Ball GT
Emperor Pilaf finally has his hands on the Black Star Dragon Balls after years of searching, which are said to be twice as powerful as Earth's normal ones. Pilaf is about to make his wish for world domination when he is interrupted by Gokuu Son. As a result, Pilaf flubs his wish and accidentally turns Gokuu back into a child.
After the wish is granted, the Black Star Dragon Balls scatter across the galaxy. However, Gokuu discovers that they will cause the Earth to explode unless they are all brought back within a year. Uniting with his granddaughter Pan and a young adult Trunks, Gokuu sets off on an adventure through the universe to find the Black Star Dragon Balls and save his planet from destruction.
(Source: MAL Rewrite)