A warning against aldgoat horns: they must be incapacitated to have a chance of dropping. You need to use skull sunder, bloodletter, spirits within, or concussive blow often and/or hard enough to break them (it will visibly appear broken off on the goat) and use it from the correct angle. I'm not sure if its horns require you to use it from the side or the front though. Incapacitation is a bit tricky.