It was a short blow, just to keep her from biting you, but the head blows she'd already taken seemed to help halt her. Unfortunately, exoskeleton was hard and better protected than your skin. Sure, blow for blow, you were pretty sure your skull could handle the same punishment, probably even outmatch any of these Changelings. However, you still had blood and flesh and nerves on the outside that made the headbutt more painful for you. Even more so, she had a fucking horn. You didn't hit it, but you had to be careful, especially after you reared your head back and repeated the motion, now with more momentum, slamming as best you could just over her right eye. The impact jarred her as her head bounced back, but you could still hear her hissing, so you did it again. And again. And again.