Well, Saiyan do naturally have prehensile monkey tails ...
And ecologically speaking, as a species, they're Super Apex predators, evolved to hunt technological species, even though they're not tool-makers in and of themselves; they're just smart enough to learn how to use them, though, and that's where Frieza comes in. He basically taught a primate version of Wolfen how to use guns.
Uh-oh, Sean Schemmel isn't a shapeshifting space monkey, so I guess he can't be Goku any more?
Well, Saiyan do naturally have prehensile monkey tails ...
And ecologically speaking, as a species, they're Super Apex predators, evolved to hunt technological species, even though they're not tool-makers in and of themselves; they're just smart enough to learn how to use them, though, and that's where Frieza comes in. He basically taught a primate version of Wolfen how to use guns.