Severus Snape

Full name: Severus Snape (SEV-er-us Sn-APE)
Role in the books Potions, and then later Defense Against the Dark Arts, professor at Hogwarts, Harry's most hated teacher, Dumbledore's helper
Actor: Alan Rickman
Age: 31-38
Born: 9th January 1960
Died: 1st May 1998
Blood status: Half-Blood
Family: Mother: Eileen Prince; Father: Tobias Snape
Place of residence: Hogwarts; during the summer, a house called Spinner's End in an industrial town or city somewhere
Occupation: Potions teacher at Hogwarts, later Defence Against the Dark Arts teacher, and then headmaster
Eyes: Black and cold
Hair: Black, shoulder-length, greasy
Other features of appearance: Hooked nose, sallow skin
Wand: Unknown
At Hogwarts: 1971 - 1978; Slytherin
Key personality traits: Brave, loyal, bitingly sarcastic, vindictive, a bully, resentful, obsessive, impatient, unforgiving
First appearance in story: Professor Quirrell, in his absurd turban, was talking to a teacher with greasy black hair, a hooked nose and sallow skin. It happened very suddenly. The hook-nosed teacher looked past Quirrell's turban straight into Harry's eyes - and a sharp, hot pain shot across the scar on Harry's forehead... The pain had gone as quickly as it had come. Harder to shake off was the feeling Harry had got from the teacher's look - a feeling that he didn't like Harry at all. (PS ch.7, pg.94)
Exit from the story: There was a terrible scream. Harry saw Snape's face losing the little colour it had left, it whitened as his black eyes widened, as the snake's fangs pierced his neck, as he failed to push the enchanted cage off himself, as his knees gave way, and he fell to the floor. [...] Harry took off the Invisibility Cloak and looked down upon the man that he hated, whose widening black eyes found Harry as he tried to speak. Harry bent over him; and Snape seized the front of his robes and pulled him close. [...] "Look... at... me..." he whispered. The green eyes found the black, but after a second something in the depths of the dark pair seemed to vanish, leaving them fixed, blank and empty. The hand holding Harry thudded to the floor, and Snape moved no more. (DH, ch.32, pg. 528)
Key life moments: Meeting Lily Evans; going to Hogwarts; meeting James, Sirius, Remus and Peter; falling in love with Lily; calling Lily a mudblood and losing her friendship; joining the Death Eaters; overhearing the prophecy and reporting it to Voldemort; changing to Dumbledore's side of the war; the death of Lily; meeting Harry; trying to save Harry from Quirrell; trying to capture Sirius and hand him over to the Dementors; returning to the Death Eaters on Dumbledore's orders; trying to teach Harry Occlumency; saving Dumbledore's life after he was cursed by the ring horcrux; finding out about Dumbledore's plan for Harry to sacrifice himself; agreeing to kill Dumbledore if need be; making the Unbreakable Vow with Narcissa; killing Dumbledore; becoming Headmaster of Hogwarts; planting the sword of Gryffindor for Harry to find and leading him to it; being killed by Nagini and giving Harry his memories as his last act