Remus Lupin is a character from the Harry Potter franchise, introduced in The Prisoner of Azkaban. He is the former professor of the Defense against the Dark Arts and mentors Harry throughout the novel. Remus is secretly a werewolf and being bitten by Fenrir Greyback. He later falls in love with Nymphadora Tonks and marries her.
In the film series, Lupin is portrayed by David Thewlis as an adult, and by James Utechin as a teenager.
Professor Remus John Lupin, O.M. (First Class), (10 March, 1960 – 2 May, 1998), also known as Moony, was a half-blood wizard and the only son of Lyall and Hope Lupin (née Howell). He was afflicted with lycanthropy during his childhood, as a result of Fenrir Greyback's revenge against Lyall. He attended Hogwarts School of Witchcraft and Wizardry from 1971-1978 and was Sorted into Gryffindor House. During his school years he was one of the Marauders, best friends with Sirius Black, James Potter, and Peter Pettigrew. Together they created the Marauder's Map.
After Hogwarts, Remus and his friends joined the original Order of the Phoenix and fought in the First Wizarding War. However, Pettigrew betrayed James and Lily Potter to Lord Voldemort a week after he was made the couples' Secret Keeper. Thus Remus had lost all of his closest friends in various ways by the end of the First Wizarding War. The loss of his friends devastated him, though he and Sirius Black later rekindled their friendship.
Remus taught at Hogwarts School of Witchcraft and Wizardry as Professor of Defence Against the Dark Arts during the 1993-1994 school year. Remus was regarded by students to be the best Defence teacher they have had thus far. He was also a professor of Harry Potter (James' son) whom he taught how to conjure a corporeal Patronus, but resigned after Severus Snape revealed to the public that Remus was a werewolf.
He fought against Death Eaters once more in the Second Wizarding War, during which he lost his friend Sirius. In 1997, Remus married fellow Order member Nymphadora Tonks and had a son, Edward Remus Lupin, of whom he named Harry the godfather. Remus fought at the Battle of Hogwarts on 2 May, 1998, during which his wife was murdered by Bellatrix Lestrange. Remus was also murdered by Death Eater, Antonin Dolohov, during the first half of the same battle. His death was avenged by Filius Flitwick.
Remus briefly appeared again through the Resurrection Stone for Harry, along with James Potter, Lily Potter, and Sirius Black in 1998. After his death his son was raised by Andromeda Tonks and Harry Potter.
He first appears in Prisoner of Azkaban as the new Defence Against the Dark Arts teacher. Most of the students hold him in extremely high regard and love his hands-on teaching style. During his tenure, he gives Harry private lessons in casting the Patronus Charm, to aid him in fighting off the Dementors patrolling the Hogwarts grounds. It is revealed in the climax of Prisoner of Azkaban that Professor Lupin is a werewolf. He turns into a werewolf at every full moon and only retains his human mind while transformed by drinking the Wolfsbane Potion prepared for him by Snape. Hermione discovers before Harry and Ron that Professor Lupin is a werewolf after Professor Snape gives Lupin's class an assignment on werewolves. She also notices that Professor Lupin's boggart is a moon.
Dumbledore, one of the few wizards who are sympathetic towards his condition, made arrangements for Lupin to attend Hogwarts as a child, where he became close friends with James (Prongs) Potter, Sirius (Padfoot) Black, and Peter (Wormtail) Pettigrew. Until the climax of Prisoner of Azkaban, Professor Lupin believes Sirius to be guilty of betraying James and Lily and killing Pettigrew.
Upon discovering that Sirius is innocent and that the very much alive Pettigrew is the traitor, Professor Lupin helps Sirius explain the truth to Harry, Ron, and Hermione in the Shrieking Shack. However, Professor Lupin had forgotten to take the Wolfsbane Potion that night and so, when touched by moonlight, transforms into a werewolf with no control over his actions. Sirius, in dog form, drives Lupin safely away from the others into the Forbidden Forest, where he wakes the next morning restored to his human body and mind. Snape, however, furious over Sirius' eventual escape and his resultant loss of the Order of Merlin promised to him by Cornelius Fudge, publicly reveals the nature of Professor Lupin's lycanthropy. Anticipating a public outcry in response to the threat he himself agrees he poses to the students, Professor Lupin resigns from his post, much to Harry's sadness.
Long after resigning as a teacher, Lupin remains a friend to Harry. In Harry Potter and the Order of the Phoenix Lupin joins the newly reformed Order of the Phoenix and is part of the advance guard which escorts Harry from the Dursley family home in the book's opening chapters. Lupin is rarely seen in Grimmauld Place as he is often away performing secret tasks for the Order.
Later in the book, Harry sees his father and Sirius bully a school-aged Snape through Snape's memory. Lupin doesn't participate in the bullying and gives several small indications that he disapproves of his friends' behaviour, but does nothing to stop them despite being a prefect. When Harry confronts Lupin about the scene he witnessed in the Pensieve, Lupin expresses regret at never having had the courage to tell his friends when they were "out of order". He adds, however, that his friends outgrew it and became better people, and that Snape also never passed up a chance to curse them when the opportunity presented itself. Later, Lupin participates in the battle at the Department of Mysteries where he duels and overpowers Lucius Malfoy.
In Harry Potter and the Half-Blood Prince, Lupin reveals that it was Fenrir Greyback who bit him when he was a child. Towards the climax of the book, Lupin is one of the defenders of Hogwarts when Death Eaters penetrate the school, and after Dumbledore's death, it is revealed that Nymphadora Tonks has fallen in love with him despite a thirteen-year age gap. He resists becoming involved with her because of the many risks posed by his lycanthropy, and insists that she deserves someone "young and whole".
By the opening of Harry Potter and the Deathly Hallows, it is revealed that Lupin and Tonks have married. Later in the book, Lupin informs Harry, Ron, and Hermione that Tonks is pregnant. However, feeling ashamed that he has turned Tonks into an outcast and guilty that his unborn child has a high chance of inheriting lycanthropy, Lupin plans to leave Tonks and their baby. This results in an intense argument between him and Harry, who insists that Lupin's actions are cowardly. Eventually, Lupin recognises the truth in Harry's words and returns to his wife in time for the birth of their son, Teddy Lupin, and subsequently asks Harry to be the boy's godfather, a duty and honour which he accepts.