Neandor

Neandors (Latin: Homo sapien hyannothus) are creatures which appear in Games Workshop’s Warhammer 40,000 universe.

Overview
Virtually nothing is known about the Neandors save that they are humanoid creatures found only on the planet Hyannoth IV, and that they are one of the few species classified by the Imperium of Man - an institution renowned for its extreme intolerance of anything strictly non-human - as a strain of Abhuman, a species which falls within the acceptable boundaries of “biologically human.”

Those few who know of the existence of Neandors theorise that they are simply former colonists of a world who devolved to the level of cave-dwellers. This theory is mostly justified by their designation - the name Neandor being very similar to Neanderthal, a type of prehistoric man - and the fact that this sub-species of humans is incapable of space travel.