Reavers are an idea that's popped into my head lately. They're soul harvesting creatures that serve some dark master with intentions unknown. They're... typically only clothed in a few rags, and have heads that vaguely resemble goats.
they typically don't show any emotion, feelings, or independent thoughts

there are a few that have 'awakened', and grown their own personalities. typically these ones dress in tight punk-rock fashion, with lossa spiked collars and stuff.