3. Which Death Eater, often thought to be insane, was killed by Molly Weasley in the Battle of Hogwarts, which occurred in "The Deathly Hallows"?
From Quiz Dark Wizards: The Death Eaters
Answer:
Bellatrix Lestrange
Molly Weasley and Bellatrix Lestrange started to duel in the Battle of Hogwarts, when Molly saw that Bellatrix almost killed her only daughter, Ginny. While they dueled, Bellatrix teased Molly about her dead son, Fred, which angered Molly so much that she sent a lethal curse and killed Bellatrix. Lord Voldemort became very angry, as Bellatrix was his most loyal follower, but before he could kill Molly Weasley, Harry showed himself.