He is a hateful evil bully, who willingly joined Voldemort.
because of harrys dad
Severus Snape took many points away from Gryffindor throughout the years. He Favorited Slytherin house and had a grudge against Harry's father, so took it out on Harry.
Because in Harry Potter and the Deathly Hallows it turns out that Professer Severus Snape was a incredibly brave man so Ginny and Harry named their kids Albus(after Dumbledore) Severus(after Snape)
Severus Snape is the half-blood prince because his mother descended from an old pureblood family, the Prince family. His mother married a Muggle, though, so that makes him a half-blood.
Severus Snape is named the new Hogwarts Headmaster. He continues to pretend to be on Voldemort's side and is always consulting Dumbledore's portrait, he suggests the idea of the seven Potters to Mundugus and only tells part of the plan to Voldemort. He also gives Harry the sword so he can destroy the Horcruxes. Voldemort thought that because Severus killed Voldemort, that Severus was the owner of the Elder wand so he has Nagini (his snake) kill him. As Snape is dying he gives Harry's his memories which helps to fill in the gaps of the story.
Severus Snape's father was a muggle and he always fought with Snape's mother. This led to Snape hating his father and therefore muggles. So he believed what Lord Voldemort believed and signed up to help him.
because of harrys dad
Maybe Hair Oil
Snape was in love with Lily and so his patronus took the shape of hers.
Because in Harry Potter and the Deathly Hallows it turns out that Professer Severus Snape was a incredibly brave man so Ginny and Harry named their kids Albus(after Dumbledore) Severus(after Snape)
Severus Snape took many points away from Gryffindor throughout the years. He Favorited Slytherin house and had a grudge against Harry's father, so took it out on Harry.
Severus Snape kills Albus Dumbledore,Tom Riddle kills Severus Snape(and finally Tom Riddle kills himself accidentally, but he has never been headmaster, so that doesn't matter)
Severus Snape is the half-blood prince because his mother descended from an old pureblood family, the Prince family. His mother married a Muggle, though, so that makes him a half-blood.
He wants to kill him so he could be the "master of the elder wand" (except for the fact that Snape was not ever the master of the elder wand....)
James ( Harry’s father) made fun of him at school and James stole Lily (Harry’s mother) from Snape who loved very much
severus snape was killed by voldemort voldemort was killed by harry potter molly weasley killed bellatrix lestrange severus snape killed dumbledore (dumbledore asked snape to kill him as he was dying anyway and so it wouldnt damage damage malfoys soul) fred weasley was killed, and so were lupin+tonks and many other in the great battle of hogwarts.
Minerva McGonagall was supposed to be headmistress in seventh year, but since Voldemort controlled the Ministry at that point, he wanted the school in his hands. He had thought then that Snape was loyal to him, and since Snape had worked there so long and killed Dumbledore, Voldemort put Snape in charge.