"Dragon Ball GT" chief character designer Katsuyoshi Nakatsuru said he agonized over designing Goku's Super Saiyan 4 appearance, which was the idea of the show's producers, questioning whether it was necessary to go further with the transformations. Because Super Saiyan 4 is brought about while in a Saiyan's "Ōzaru" form, he made the hair more "wild" and covered Goku's body in red fur. There was only a single final draft of the character, although Nakatsuru did consider making the hair blonde, he ended up choosing black as it provides more contrast with the red fur.