The Legion of the Maw
From Solium Infernum Wiki
Description
Feed them the heads and hands of your deceased, and they will grow in number. Then they will aid you. Feed them nothing, and they will leave their place underneath the sandy floor to seek out your beasts of burden, your slaves, and even your unbound poor. Do not fear if the floors of your temples shake like Earth’s stomach, for late is the hour to call them off. They are a voracious lot. --A message delivered by an unidentified humanoid to Lucifer’s Choir, disregarded as superstition since Maw-beasts had yet to be seen