I had an idea for horns, so even though I had nothing to add them to at that moment, I had to work them up before I forgot.
You should end up with a slightly curvy horn that is approximately 4 inches tall.
A larger or smaller hook will change the size of your horns.
I used worsted weigh yarn for mine. Thinner or thicker yarn will also change your size.

4.5MM HOOK - WORSTED WEIGHT YARN - COLOR OF CHOICE

WORKED IN THE ROUND