Kakarrot
Kakarrot is Goku’s Saiyan name. It’s what Vegeta and other Saiyans call him when they’re too lazy to say his Earth name. But everyone else calls him Goku because he’s a total goofball.
'Kakarot, why did you eat the whole pizza? You’re gonna be fat like me!', Vegeta
'I’m not a Saiyan, I’m a Kakarot!', Goku
'Kakarot? That’s the stupidest name I’ve ever heard!', Krillin