- ""Avada Kedavra!" Moody roared. There was a flash of blinding green light and a rushing sound, as though a vast, invisible something was soaring through the air - instantaneously the spider rolled over onto its back, unmarked, but unmistakably dead."
- —Barty Crouch Jr, disguised as Alastor Moody, cursing a spider[src]
The Killing Curse (Avada Kedavra) is a spell used to kill the victim instantly; it is illegal, though is used quite often throughout the twentieth century.
Harry Potter is the only known survivor of the Killing Curse and survived it multiple times in his lifetime.