Metaphor- “The creature was a party of boys (pg 16).” This choice of words also has strong symbolic meaning in the overall story. Literally, they were, as a group, working their way through a dangerous jungle. At the same time, there are dark connotations to this phrase. The way it is used makes it seem as though there is something dark and foreboding about this “creature” of boys, as though they are capable of bringing some kind of chaos or destruction to the island, which they do in the end.
Simile- "The coral was scribbled in the sea as though a giant had bent down to reproduce the shape of the island in a flowing chalk line but tired before he had finished (pg 29)." Another instance: "The breezes that on the lagoon had chased their tails like kittens were finding their way across the platform and into the forest (pg 34)." At one point, Golding writes, "The two boys, bullet-headed and with hair like tow, flung themselves down and lay grinning and panting at Ralph like dogs (not sure of the page number)."
Personification – Found in the conversation between the dead pig head and Simon. Obviously a pig would not be able to speak, and the head of a dead pig would be even less likely to speak. I believe this conversation takes place on page 41. Another example is found on page 15, "When these breezes reached the platform the palm fronds would whisper winged things in the shade." Hope this helps.
*the quote "the creature was a party of boys, marching..." is on page 19 instead of 16*