In Dragonball Z, Goku is 25. Goku usually wears an orange training outfit. A lot happens to Goku in Z: he and Chi Chi have two babies; Gohan and Goten, he finds out he’s a Saiyan, he reaches Super Saiyan level, he reaches 3 Super Saiyan levels, that nobody has ever seen or heard about, and he learns lots of new attacks and abilities. – In the first part of Dragonball GT, he is 35. And then Pilaf makes the accidental wish, to make Goku a the size he was when he was 12. And then Pan, Trunks, and Goku go on the hunt for the Darkstar Dragonballs, to reverse the wish.