I bought a digital pdf from CuteMonsterProps here, which was to scale and gave me a rough design on how to make it. Then I used a new trick I learned since my first attempt, using rough sandpaper you can smooth the clay down significantly and use Artist turpentine to clean it up (it ‘dissolves’/melts the clay shavings). Take a lump of clay and roll it into a horn shape, and alter the thinness of the base until you are satisfied.