Granolah

Granolah is the last surviving Cerealian, a race nearly wiped out by the Saiyan army acting under Frieza's orders when Granolah was a child. He spent decades hunting Frieza to avenge his people and became a bounty hunter to that end. Using the Dragon Balls of his planet, he wished to become the strongest mortal in the universe — at the cost of most of his remaining lifespan. His arc challenged Goku and Vegeta individually, and ultimately revealed that Bardock had actually saved young Granolah during the very attack he blamed all Saiyans for.