The Goyl are a humanoid race with skin of stone. They appear in the Mirrorworld series.
Man-Goyl is the term for victims of the curse inflicted by the Dark Fairy.
When a Goyl rakes a human with their claws, the human in question begins transforming a days-long process of becoming Goyl themselves.
Never before until now has the Goyl have a ruler. Before, there were only chiefs. But Hentzau and Kami'en defeat all the chiefs, and Kami'en annoints himself the first King of the Goyl, while Hentzau becomes second-in-command. This the first time a carnelian Goyl is a ruler, and a brown jasper Goyl risen to the highest ranks.
The Goyl believe that moonstone and onyx Goyls are better than other skin colours, and the onyx are the elite, similar to racism in the human world.