A very large generally angry grey female ruminant with fore and aft nose horns made of fused hair that lives in a harem group of similar vegetarian animals called a 'Crash' usually with only one mature Bull is also referred to as a 'Cow', as are the females of another large grey vegetarian with side by side large teeth (and huge flappy ears) that were likely used to make the grip on my favourite yataghan.
All can be legitimately called Cow Horn. in addition to the more usual female Bovines which generally are not greyish.
might also be Bull horn.
I doubt that any of our items were made from Bull Horns like this one tho: