Derro

A creature unique to Koganusan, the Derro were birthed from the depths of the earth that bore them, in long isolation from the living world. For centuries they dwelt in darkness, inhaling the odors of their failures and dead, believing the world above them to be lost to a cruel plague and the world beneath to be the source of crueler things yet. In the darkness, their skin took an ashen hue, their hair faded white and their minds snapped and twisted. They do not speak except in thoughts to one another and to laugh in the darkness; a bizarre punchline of the incomprehensible depths that birthed them.