The horns are made out of black fondant and there is also a recommendation for a no-taste red food coloring. I love this site and there are lots of tips, tricks and history to go along with the recipe.
For more Halloween food like spider donuts, 18 Gross Halloween Recipes, snakes on a stick, grilled turtles, spiderweb cakes and screaming pretzels go here: halloweencrafts.tumblr.com/tagged/food
This DIY uses cardboard for the collar and toilet paper rolls, tape and a hat base for the headdress
DIY Inspiration: Horned Golden Princess Makeup by Sandra Holmbom. There is no tutorial but what intrigued me about this photo was the use of long hair as horns. They actually look more organic and more sinister to me. Also, pretty positive the headpiece was made with a glue gun. Go to the link for products used and more photos. For more amazing Halloween and cosplay makeup from Sandra Holmbom go here: halloweencrafts.tumblr.com/tagged/psychosandra