The creator of Gowther the doll, Gowther fights for the demon clan, but is he a demon? Or is he a magician or another race? We know among their fighters, the demon clans had fighters from other races, such as the giant king and the fairy king, and a converted angel such as Estarossa. So, what race is he?
The original Gowther was a pure-blooded demon.
He originally lived in the Demon World with his lover Glariza as a powerful sorcerer. The Demon King eventually forced him to become one of his Ten Commandments, and locked him up in the Demon Prison to punish him for his disobedience. As proof of his demon-hood, he bears a black mark over his right eye when he escapes the Demon Prison. Those black marks are characteristic and can only be displayed by demons.