Draco Malfoy's mother and Lucius Malfoy's wife. While she does believe Voldemort's views about Muggle-borns and half-breed/half bloods are correct, she lied to Voldemort and told him that Harry was dead in the Forbidden Forest, wanting to journey up to the castle to find her son, Draco Malfoy. Once Harry's 'dead' body was taken up to the castle, Harry battled Voldemort and defeated him. After the war, this act kept her immediate family (Lucius and Draco) out of Azkaban, the wizard prison. She's a part of the black family line, sister to Andromeda Tonks (formerly Black) and Bellatrix Lestrange, although she looks down on Andromeda because she married a muggle-born, Ted Tonks.
Person 1: Narcissa Malfoy is a bitch.
Person 2: But she lied to Voldemort!
Person 1: So?
Person 2: If she hadn't, Voldemort would've won the war!
Person 1: She's still a bitch.
Person 2: You're impossible.
*begin another useless conversation*