"Goku's Great Transformation" (悟空の大変身 Gokū no Dai-Henshin) is the sixth chapter of Dragon Ball SD.
Summary[]
Pilaf's wish has been successfully thwarted, but now Goku & co. are in an even more inescapable prison, which will cook them alive in the midday sun. But just then, Goku tells them about the monster that comes out in the full moon. Faced with a monstrous ape Goku, the others must survive the night and return Goku to normal.