Who kills Jack at the end of chapter seven?
As the previous poster pointed out, Jack is not killed in The Lord of the Flies. The list of the people killed in the story is as follows:
1. The first boy to die is the boy with the mulberry colored birthmark, the boy who first comes into the story when he talks about the snake-thing that he saw in the night that is then labeled the beast. He dies in the fire that burns a big swath of jungle after the fire atop the mountain.
2. The second boy to die is Simon. When he stumbles out of the jungle and into the midst of the boys dancing and pretending to kill the beast, they react in terror and beat him to death.
3. The next boy to die is Piggy. When Ralph and Piggy go to castle rock to attempt to negotiate with Jack, Roger tumbles a giant stone down from atop a cliff and crushes Piggy (and the conch) beneath it.
Jack and his hunters try to find Ralph to kill him but he is saved at the last minute by the appearance of the naval officer.
Jack is not killed during the novel "Lord of the Flies". Only two of the boys are killed, Simon and Piggy. Both of these boys are killed by the other boys when they are overcome by savagery. The person who dies in Chapter 7 seems to be Simon whom the boys kill because they believe he is the beast. They work themselves up into a frenzy and horrifically murder him.