Feldon
From EverQuest2.com: Deep underneath Norrath lies a realm, on the edge of the Plane of the Underfoot, known as Thalumbra. Though long thought of as the domain of Brell Serilis, unlucky explorers and inexperienced spelunkers quickly find the denizens of below are not limited to those of his creation. This expansive, subterranean kingdom is home to fabled races, and ancient, unimaginable terrors, including Aberrants, poxfiends, fathomlurkers and cepholex! Here, under innumerable layers of stone, their eternal struggle to survive has shaped them, forcing them to develop sophisticated weapons or intricate defenses.