One of the big themes of the book is built around the way the boys start off relatively civilized and finish the book in an almost completely animalistic state, barely able to even communicate with the officer from the boat, the representative of society.
When the boys first reach the island, they are still fully clothed, the choir boys are in uniform, there is a great deal of decorum still to be seen.
Rather quickly their appearance begins to reflect their situation, and as they go longer on the island, they begin to paint their bodies, to look more and more like the animals which they are beginning to resemble in their actions as well.
At the beginning of the narrative of Lord of the Flies, of course, the boys are well-groomed; Ralph looks like the "golden boy," the ideal look at the time of the novel's writing; he is tall, good-looking, athletic, and charismatic. In contrast to Ralph, Piggy is a boy in a middle-aged man's body. His hair is already thinning, he is myopic, and he is overweight and unathletic. Piggy also suffers from asthma. Appearing rather abruptly, Jack, tall with red hair, marches the other boys of the choir up to Ralph and Piggy. He wears the black cap and cape of his occupation and looks the part of a leader.
After a while, the little boys appear; one of them has a mulberry mark on his face, and, like one marked in the Bible, he is cursed as he quickly disappears and is never seen again. Percival and Johnny are the smallest of the very young boys. Johnny has fair hair and "a natural belligerence."
Simon is a middle-sized boy with dark hair that often falls in his eyes, symbolizing that his "sights" are intuitive rather than merely visual. He is kind and helpful, but an independent thinker always.
After the boys have lived on the island, of course, their hair becomes longer and disheveled, their clothes dirty and torn, and some things have been discarded. It is interesting that one character, Roger, who keeps to himself with "an inner intensity of avoidance," is not described physically at the beginning of the narrative, but it is written that he is fascinated when he sees that Jack has a mask on his face which disguises him. Quickly, Roger adopts the wearing of a mask which can "liberate him from shame and self-consciousness" of the rules of society. In one of the final chapters, Roger, then, releases the boulder that sends Piggy to his death with "delirious abandonment."