a few minutes ago I made the burnt Astrid my thrall with the dead thrall spell.
Damn, that means you got a thrall that actually looks like a zombie.
I don't really use thralls alot, but I'm quite sure I enslaved miss.Nazeem before.
http://cloud-2.steampowered.com/ugc/576740855282358716/85144B5D06F9953D3FAE67537CE25480805649BA/