- Hermione finds bicorn horn in the list of ingredients for Polyjuice Potion in the book Most Potente Potions, found in the Hogwarts Library Restricted Section.
- Hermione stole bicorn horn from Professor Snape's Office after Harry and Ron created a diversion by blowing up Goyle's cauldron.
- The author wrote on Pottermore that she chose Bicorn Horn for Polyjuice Potion because of "duality." Just as the Bicorn has two horns, a wizard uses Polyjuice to masquerade as someone else while keeping their own identity.
Powdered horn used in Polyjuice Potion.