The Burrowing Conquerers, or Helleautaurides as they call themselves, are creatures of the underworld.
A fully-grown Helleautauride looks like a human child on the left side of its body, a zebra on the right (children of this species look like a human fetus on the left side and a zebra fetus on the right).
They walk on all fours, but sit human-style, allowing them to manipulate objects using their left hand (and to a lesser extent their left foot).
Their nickname comes from their habit of digging a hole in the ground and then burying themselves in order to sleep. They are most comfortable doing so in areas shaded by trees, implying that they may have originated on the surface.
The 'conquerer' in their name may be a sarcastic reference to their small size and awkward frame. The name may refer to their mercantile skill, which has meant that they are spread throughout the underworld (they are particularly fond of trading clocks). It may also refer to their domination of the Bright Peacocks. They are most reluctant to risk their lives, but may be dangerous if cornered - especially since a blow from their fists may cause a wizard to forget spells, or rob magic items of their virtues.