Dragon Ball originally had a completely different design from what we've seen in the manga and anime.
The development process of Dragon Ball by Akira Toriyama was an evolutionary one, undergoing several revisions before reaching an iconic form.
The first drawing of Goku and the reason it was rejected
Initially, Toriyama drew inspiration from Journey to the West with the aim of a more realistic adaptation. At this stage, the character Son Goku was described quite literally as the 'Monkey King.' Other characters were no exception, for example, the first version of Pigsy bore a striking resemblance to Zhu Bajie.
However, this initial approach was rejected for being too similar to the original Journey to the West. Toriyama's wife and other critics did not favor this version, leading to significant changes. Kazuhiko Torishima, Toriyama's original editor, also emphasized the importance of emotional connection between the readers and the main character, something a monkey character would struggle to achieve.