Irma Pince is the Hogwarts Librarian, a position she has held for many years. She is known for her strict adherence to library rules and her vast knowledge of magical books. Her full name is Irma Pruneface, but she is commonly referred to as Pince, which is derived from her surname. She is a formidable figure in the library, and is often seen wearing a pin with the initials 'IP' on it, which stands for Irma Pince.