The most toughest and typical fictional character in the entire series was of Severus Snape. Appeared as servant of dark lord in the all parts and at the end of the movie the truth revealed that he was the second God Father of Harry Potter. He is described as a horrible teacher because his true loyalties and motivations were not revealed until the final part. He is the school's Potions Master, though he is widely rumoured to covet the Defence Against the Dark Arts post.Snape is a sinister and malicious teacher who makes frequent snide and disparaging remarks at Harry's expense. He quickly becomes the primary antagonist of the book, as Harry suspects him of plotting to steal the philosopher's stone.Only the climax of the book reveals that Professor Quirrell, in league with Lord Voldemort, is the real enemy; Snape, suspicious of Quirrell, had been looking out for Harry throughout the book.In Harry Potter and the Prisoner of Azkaban, Snape demonstrates his expertise with potions by brewing the complex Wolfsbane potion for the new Defence Against the Dark Arts professor, Remus Lupin. In Harry Potter and the Deathly Hallows, Snape is named Headmaster of Hogwarts, while Death Eaters Alecto and Amycus Carrow are appointed to the Hogwarts staff.The truthlater reveals that Snape uses his position as Headmaster to protect the students and to contain the Carrows. At the end Lord Voldemort betrays Snape and has his pet snake Nagini bite him through the neck, mortally wounding him, believing that Snape's death will make him the master of the Wand.[42] Snape, dying from his wounds, releases a cloud of memories and tells Harry, who has watched the entire scene from a hidden spot, to take them.From these memories, Harry sees Snape's childhood and learns his true loyalties.Snape's memories then reveal that Dumbledore had been afflicted by a powerful curse cast on the Gaunt ring, one of Voldemort's Horcruxes, prior to the start of Harry's sixth year at Hogwarts.Snape became a re-doubled agent for the Order of the Phoenix against Voldemort, using his powers of Occlumency to hide his betrayal from his master. Even with his efforts to protect her, Snape felt responsible for Lily's death when the Potters were betrayed by their Secret-Keeper, Peter Pettigrew. Snape demanded of Dumbledore, however, that his love for Lily be kept a secret. Dumbledore agreed and he kept the secret for the rest of his life.
Although Snape's knowledge of the Dark Arts enabled him to slow the spread of the curse, the curse would have ultimately killed Dumbledore within a year. Snape's memories also provide Harry with the information he needs to ensure Voldemort's final defeat, in the form of conversations Snape had with Dumbledore.