He is described to be short, black-haired and dark-skinned. In the 1963 film he is pale with blond hair. He was created after Peterkin Gay. In the 1990 film, he is played by James Badge Dale who had red hair and green eyes.
Whereas Ralph and Jack stand at opposite ends of the spectrum between civilisation and savagery, Simon stands on an entirely different plane from all the other boys. Simon embodies a kind of innate, spiritual human goodness that is deeply connected with Nature and, in its own way, as primal as Jack’s evil. The other boys abandon moral behaviour as soon as civilisation is no longer there to impose it upon them. They are not innately moral; rather, the adult world—the threat of punishment for misdeeds—has conditioned them to act morally. To an extent, even the seemingly civilised Ralph and Piggy are products of social conditioning, as we see when they participate in the hunt-dance. In Golding’s view, the human impulse toward civilisation is not as deeply rooted as the human impulse toward savagery. Unlike all the other boys on the island, Simon acts morally not out of guilt or shame but because he believes in the inherent value of morality. He behaves kindly toward the littluns, and he is the first to realise the problem posed by the beast and the Lord of the Flies—that is, that the monster on the island is not a real, physical beast but rather a savagery that lurks within each human being. The sow’s head on the stake symbolises this idea, as we see in Simon’s vision of the head speaking to him. Ultimately, this idea of the inherent evil within each human being stands as the moral conclusion and central problem of the novel. Against this idea of evil, Simon represents a contrary idea of essential human goodness. However, his brutal murder at the hands of the other boys indicates the scarcity of that good amid an overwhelming abundance of evil.
He is killed by the group of boys led by Jack. Roger and the rest of feral tribe murdered him by beating him to death, with his body to be washed away at sea. Ralph greatly regretted his actions with Piggy reassuring him that it wasn't his fault.