Dragonball GT

Taking place 10 years after the final Dragonball Z story, Emperor Pilaf finally manages to get all 7 dragonballs and makes a wish. Unfortunately for Pilaf, he gets flustered by the presence of Goku and wishes for Goku to be a child again so that Pilaf could "teach him a lesson." Pilaf gets his wish, and Goku is off on an interstellar trip to gather the 7 "Black Star Dragonballs" that can reverse the wish and return him to adulthood. The Black Star Dragonballs also have lethal side effects. After a wish has been granted, the Black Star Dragon Balls spread all over the galaxy. If all seven balls are not re-collected and returned to the planet on which the wish was granted, the planet will explode. Goku and Vegeta also turn Super Saiyan 4 in this series and also fuse to form Gogeta.