Behind the scenes
- The use of the horn of a Bicorn in the Polyjuice Potion was chosen by J. K. Rowling to represent "the idea of duality".
- Harry Potter and the Philosopher's Stone (video game) (GBC version only)
- Harry Potter and the Chamber of Secrets (First appearance)
- Harry Potter and the Chamber of Secrets (video game)
- Harry Potter and the Half-Blood Prince (film) (Mentioned only)
- The Road to Hogwarts Sweepstakes