There are several different kinds of Darkspawn. I have only fought two in my days as a mercenary.
Genlocks: Short, but with long-ass arms. They tend to walk on their knuckles, and move surprisingly quickly. They also pack a heckuva punch and grasp. Very annoying.
Hurlocks: These guys kinda look like a man, if something ate his face off his skull, and sharpened his teeth. They're not quite as fast or strong as their short brothers, but they compensate with weapons and armor.