In Lord of the Flies, Jack represents the savagery or evil in man. He loses his ability to remain civilized while he is stranded on the island. He gives in to his innate savagery and becomes dehumanized. He becomes a wretched evil person. He becomes blood thirsty and slaughters pigs unmercifully. He laughs and shakes the blood from his hands after killing a sow. He laughs as Roger probes the sow's anus with his spear. Jack laughs as Roger twists and puts all of his weight on the spear while the sow screams in agony:
Jack begins to rub the blood on his hands onto Maurice, and then they notice Roger withdraw his spear. They become hysterical because he had pinned the sow by driving the spear through its anus. They reenact the slaughter until they grow tired.
Then, Jack hangs the sow's head on a stick to represent the Lord of the Flies. He becomes cruel in his killing of the sow. Then he leads his mighty hunters into a hunting-dance frenzy. During the dance frenzy, Simon comes crawling out of the woods and Jack and his hunters jump on him and kill him with their bare hands and teeth. No doubt, Jack represents the most evil nature a man can have--a complete lust for blood and the power of the hunt:
He represents leadership by intimidation and rebelliousness. By the end he is compared to an “ape” and called a “savage.”
Ralph, Piggy and the littluns represent innocence. They are the good that is found in mankind. They despise Jack's and his blood thirsty hunters' actions. Ralph and Piggy try to keep order on the island, but it is hopeless to change Jack and his hunters. In particular, Ralph tries to get everyone to build shelters and a fire to quicken their rescue:
[Ralph] is elected leader and initiates necessity to build shelters and a fire. He represents leadership by common sense and governmental authority.
Ralph and Piggy represent sense and order in all the chaos created by Jack and his hunters. Piggy dies a senseless death at the hand of Roger who is utterly cruel. By the end of the story, Ralph is being hunted by Jack and his hunters. Ralph and his representation of good versus evil is losing the battle. If the naval officer had not arrived when he did, Ralph very well may have killed by Jack and his cruel hunters.