Parseltongue

Parseltongue is the magical language of serpents in the Harry Potter universe, spoken by rare witches and wizards known as Parselmouths. While J.K. Rowling created the concept, phonetician Francis Nolan of Cambridge University developed the spoken version for specific Harry Potter films including Goblet of Fire and Deathly Hallows Part 1. The language features heavy sibilants and hissing sounds designed to mimic snake vocalizations. In the story, it is associated with Salazar Slytherin and is considered a dark ability, though Harry Potter himself is a Parselmouth.