The creature

 It crawled across the ground toward it's victim.  What is it? Something from out of this world,  is the best answer.   Thin body, scaly reptile like skin.  Razor sharp spikes down it back, Razor sharp claws on its feet and hands.  When it opened it's mouth,  Razor sharp teeth,  layer upon layer rotating like a chainsaw.   Blood shot eyes. The head a cross between human and reptile.   That is the best I can do at describing such a hellish creature,  and that is just from what I heard.  For this happened many, many centuries before my birth.