Gorr the God Butcher is an alien from an unnamed planet, harbouring an intense hatred for gods, due to false beliefs and hopes that the gods would reach and protect him and his family when needed.
Gorr was once a simple man living on a dying alien planet, constantly wracked by famine, predators and natural disasters. His species was very pious, constantly praying to the gods for help, but that did not save Gorr's mother from being torn apart by carnivores, his wife (pregnant with his child) from being swallowed into the ground by an earthquake, and his son from starving to death as Gorr tried in vain to console him. As a result, Gorr began to doubt the existence of Gods, which led him to getting exiled from the tribe. In his exile, Gorr observed a battle between two gods that left them mortally wounded and fallen to the ground. In that moment, Gorr's doubt turned into hate.
When dealing with gods, Gorr is fantastically cruel. He revels in making deities suffer and tries to make their agonies last as long as possible, regardless of what they are gods of. Throughout the series, Gorr is called out several times on the fact that, in his quest to kill all gods, he has himself become the very worst god of all - immensely powerful, power-abusing, completely devoid of all empathy. He also seems to have lost his mind over the millennia, to the point that by the end, he was willing to kill his own wife (technically a copy of her) just for calling him a God.