Yes, you will eventually unlock a quest to get the Goatperson. I haven't played far enough through the normal progression to know where it first becomes available, but on my game where I've unlocked everything, I had to do an additional quest to unlock him.

In order to unlock the Goatperson, you need to purchase his building at a relatively steep price of 3000 kingdom gold. The building seems to first appear when you beat the Frozen Tundra quest. But you'll likely need to keep questing for a while before you can actually purchase it, since your kingdom bank needs to be upgraded to be able to hold that much gold.