Remus John Lupin is a fictional character in the Harry Potter book series written by J. K. Rowling. He first appears in Harry Potter and the Prisoner of Azkaban as the new Defence Against the Dark Arts professor. Lupin remains in the story following his resignation from this post, serving as a friend and ally of the central character, Harry Potter. In the films, he is portrayed by David Thewlis as an adult, and James Utechin as a teenager.

Magical creatures are an aspect of the fictional Wizarding World contained in the Harry Potter series and connected media originally created by British author J. K. Rowling. Throughout the seven main books of the series, Harry and his friends encounter many of these creatures on their adventures in Hogwarts, the Forbidden Forest, or other locations throughout the Wizarding World. In addition, students learn to take care of creatures such as hippogriffs and unicorns in the Care of Magical Creatures class at Hogwarts. Rowling has also written Fantastic Beasts and Where to Find Them, a guide to the magical beasts found in the series, and based on the fictional textbook of the same name written by Newt Scamander and used by students at Hogwarts.