Quirinus Quirrell

"No dear boy. I tried to kill you. And trust me. If Snape's cloak hadn't caught fire and broken my eye contact I would have succeeded. Even with Snape muttering his little counter curse."

- Professor Quirrell revealing his true colors

Professor Quirinus Quirrell is the main antagonist in the first Harry Potter book and movie, Harry Potter and The Philosopher's Stone as revealed during the climax. He was a dark wizard and a Defense Against the Dark Arts teacher during Harry Potter's first year at Hogwarts. He is portrayed by Ian Hart, who also does the voice of Voldemort in the same film.

Quirrell was once an insecure and stuttering man. When he was a student at Hogwarts, he was sorted into Ravenclaw house. J.K. Rowling stated that he was teaching Muggle Studies before taking over Defense Against the Dark Arts. He traveled around the world to get subject for his lessons and during one of these travels, he met the desincarnate Lord Voldemort, who gained him to his cause. From then on, the shy, young teacher would become much more confident and ruthless, though he kept acting like his old self as a facade.

Quirrell breaks into Gringotts the Wizards Bank and fails to steal the Philosophers Stone, getting possessed by Voldemort as a punishment. He then starts to wear a turban to conceal Voldemort's face in the back of his head. During the first book, Quirrell tries to steal The Sorcerer's Stone, which is hidden in the third floor corridor of the school of Hogwarts. He keeps failing due to the magical protection and Severus Snape's constant watching. Near the end of the school year, Harry discovers Quirrell who is about to steal the Stone. Upon Voldemort's orders, Quirrell attempts to kill Harry, but he could not bear the touch of the young wizard, who is protected by the magic of his mother's sacrifice, and ultimately dies when Voldemort left his body.

Archive footage of Quirrell sitting next to Snape in Harry Potter and the Philosopher's Stone is used in ''Harry Potter and the Deathly Hallows: Part 2. ''This footage continues with Quirrell turning into black smoke and disappearing to create the effects that this scene is a memory of Snape.

Trivia

 * J.K. Rowling stated that Quirrell was partly an Horcrux, because he was holding a piece of Voldemort's soul inside him. So, it can be said that Quirrell was the first Horcrux that Harry destroyed instead of Tom Riddle's Diary. However, considering the story's logic, Quirrel cannot be one, since horcruxes hold the parts of a wizard's soul that aren't with its conscience, and the one with Quirrel was the soul part which was Voldemort himself, soul and conscience.
 * The name "Quirinus" is possibly derived from the Sabine word quiris meaning "spear". Quirinus was a Sabine and Roman god who was later identified with Mars. The name was also borne by several early saints.
 * Professor Quirrell was the second-to-final boss in the Gameboy color adaptation of Harry potter and the Sorcerer's stone.
 * ​He is also the only boss who can use level 3 magic (tria magic).
 * In Jimmy Neutron Carl played a character based off of Quirinus and Tom Riddle from the Chamber of Secrets (with the former being a vessel for Voldemort and the later being an Incarnation of Voldemort).