Narcissa Malfoy

Narcissa "Cissy" Malfoy, born Narcissa Black to Cygnus Black and Druella Rosier, is the youngest of three sisters, Bellatrix Lestrange and Andromeda Tonks being her older siblings. She is a cousin of Sirius and Regulus Black and an aunt to Nymphadora Tonks, daughter of her sister Andromeda. Narcissa attended Hogwarts, where she was in Slytherin House. She later married Lucius Malfoy, with whom she has one son, Draco. Although never a Death Eater herself, Narcissa shares her husband's views on blood purity. She is first described as a tall, slim, blue-eyed blonde who would have been attractive had it not been for "a look that suggested there was a nasty smell under her nose."
Although Narcissa makes her first, very brief appearance in Goblet of Fire, where she attends the Quidditch World Cup with her husband and son, her role in the series first becomes important in Harry Potter and the Half-Blood Prince. Near the beginning of the book, Narcissa and Bellatrix arrive suddenly at Snape's Spinner's End home. Narcissa is distraught, almost hysterical, with her husband imprisoned in Azkaban and her son forced to accept a difficult and dangerous assignment by Voldemort. She begs Snape to help Draco and asks him to make an Unbreakable Vow, to which he agrees, despite the astonishment and suspicion of Bellatrix. Later in the novel, Narcissa appears shopping with Draco for his new robes at Madam Malkin's. She and Draco mock Harry when he enters the shop with his friends, Ron and Hermione. Harry, Ron, and Draco nearly start a duel, but Narcissa defuses the situation by leaving with her son. It is evident that Narcissa is highly protective of her only child, to the point that Draco loses his patience and snaps at her that he is "... not a child, in case you haven't noticed, mother. I am perfectly capable of doing my shopping alone".
In Deathly Hallows, Narcissa's home, Malfoy Manor, is being used (against her will) as the Headquarters for Voldemort and his Death Eaters and for confining several prisoners, including eventually, Harry, Ron, and Hermione. When this group escapes with the help of the house-elf Dobby, Voldemort places Narcissa and her family under house arrest. In the climax of the book, the Malfoys are brought with the other Death Eaters to Hogwarts, when Voldemort invades the castle. After Voldemort casts a Killing Curse on Harry, and after the boy returns to consciousness but is still pretending to be dead, Narcissa is ordered by Voldemort to confirm his death. Realising that Harry is not dead after feeling his heart beating, she quietly asks him whether Draco is still alive at Hogwarts, knowing that she will not be free to search for her child unless she can return with the Death Eaters as part of a "conquering army." Harry confirms that Draco is alive, so Narcissa lies to Voldemort, claiming that Harry is indeed dead. She is later seen at the end of the book, with her husband and son, unsure what to do and how to behave amidst the celebration of Voldemort's death. However, thanks to her lie to Voldemort, the Malfoys manage to "weasel their way" out of imprisonment in Azkaban.
She will be portrayed by actress Helen McCrory in the film adaptation of Half-Blood Prince.