A Voormis.

The Voormis are a race of cave-dwelling humanoids who worship Tsathoggua. The Voormis had, from their remotest origins, considered themselves the chosen minions of Tsathoggua, the sole deity whose worship they celebrated. And Tsathoggua was an earth elemental ranged in perpetual and unrelenting enmity against the Rhan-Tegoth and all his kind, who were commonly accounted elementals of the air and were objects of contempt to those of the Old Ones, like Tsathoggua, who abominated the airy emptiness above the world and by preference wallowed in darksome and subterranean lairs.

The Voormis are described as three-toed, umber-colored, fur-covered humanoids though they are carefully differentiated from their traditional enemies (the shaggier-haired but superficially similar Gnophkehs who worshiped the Great Old One Rhan-Tegoth). Both of them are further differentiated from true humans. The Voormis communicate by dog-like howls.

They reside in a continent in Hyperborea which will be known in the future as Mhu Thulan. Specifically in cave systems under the four-coned extinct volcano named after them, Mount Voormithadreth, the tallest peak in the Eiglophian mountains. Their ancestors  were originally thralls of the Serpent-people who escaped after the continent of the latter sank to the sea.

They are shamanistic and apparently begun dwelling underground in an effort to imitate their deity, Tsathoggua, under the leadership of the eponymous Voorm. The Voormis established a thriving culture in the surface Hyperborea before the coming of humans;establishing citadels in the island of Ta-Shon and adding to the arcane knowledge of the Pnakotic Manuscripts.

Their civilization eventually fell into demise. With constant warfare with their archenemies, the Gnophkeh, they grew smaller and smaller in number until the remnants retreated to the highest slopes of the Eiglophian mountains. They were hunted for sport by later human settlers.