A Potions professor at Hogwarts school in the Harry Potter series.
Snape is generally described as hook-nosed, greasy-haired, pale and thin. His demeanor towards Harry Potter is closest to loathing, for reasons unbeknownst to Harry, until the 7th Harry Potter book. In the final installment, Harry discovers that Snape loved his mother Lily. Snape also despised Harry's father, James, perhaps because of jealousy.
Although Snape hates Harry due to Harry's resemblance of James Potter, he sees his own love's eyes in Harry. Snape is largely responsible for saving Harry's life throughout his school career by working as a double agent for Dumbledore. His death is quick and without glory, but Harry spreads the knowledge of Snape's bravery in the years after his death.
Insert a beautiful doe Patronus, the same Patronus as his unrequited love's, Lily Evans, performed by Snape.
Dumbledore,with tears in his eyes: All this time?
Severus Snape: Always.