How do Sam and Eric exaggerate what they saw?

They say it had big teeth and claws and chased them.

When Sam and Eric wake up, they tend to the fire to make the flames brighter. In the flickering firelight, they see the twisted form of the dead parachutist and mistake the shadowy image for the figure of the dreaded beast. They rush back to the camp, wake Ralph, and tell him what they have seen. Ralph immediately calls for a meeting, at which the twins reiterate their claim that a monster assaulted them. The boys, electrified and horrified by the twins’ claims, organize an expedition to search the island for monsters. They set out, armed with wooden spears, and only Piggy and the littluns remain behind.

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