<P> Severus Snape is a fictional character in J.K. Rowling 's Harry Potter series . An exceptionally skilful wizard , his coldly sarcastic and controlled exterior conceals deep emotions and anguish . A Professor at Hogwarts School of Witchcraft and Wizardry , Snape is hostile to the series ' protagonist , Harry , the moment he sets foot in Snape 's classroom ; this hostility is rooted in Harry 's resemblance to Harry 's father James , who bullied and harassed Snape during their time at Hogwarts . Though philosophically attracted to the Dark Arts and Lord Voldemort 's ideology of wizard supremacy , Snape 's love for Muggle - born Lily Evans , Harry 's mother , eventually compels him to defect from the Death Eaters . Snape becomes a double - agent on behalf of Albus Dumbledore and the Order of the Phoenix , and protects Harry throughout the series . </P>
who is snape in relation to harry potter
Professor at Hogwarts School of Witchcraft and Wizardry