Dragon Ball GT - episode 1 - 06 Feb, 1996

As Goku and Uub fight inside Dende's lookout, Emperor Pilaf scales the outside of the lookout, and sneaks in to the inner chamber, unnoticed. He finds the Black Star Dragon Balls, and summons the dragon so he can wish to take over the world. After Goku and Uub finally ended their training and Uub leaving the lookout after bidding farewell to Goku, Pilaf was about to wish to take over the world until he is interrupted by Goku and Pilaf orders his assistants, Shu and Mai to fire the missiles at Goku, but Goku stops the missiles. Frustrated, he says that he wishes Goku were a child again so he could beat him up. The dragon grants this accidental wish, and Goku becomes a child. After Pilaf leaves, King Kai tells Goku that the only way he can return to normal is by finding the Black Star Dragon Balls, which are now scattered throughout the galaxy. However, Goku decides it will be easier to just grow up again, and he heads into town. There he finds Pan foiling a bank robbery and Pan discovers that the little boy is her grandfather after Goku sees Master Roshi again. He heads home for the first time in years with her, and explains to everyone what happened. King Kai interrupts their conversation. He has discovered that when a wish is made on the Black Star Dragon Balls, the planet the wish was made on will explode within one year unless the seven balls are brought back. (Source: Wikipedia)