What is the "beastie" in the novel Lord of the Flies?

The beastie in the novel Lord of the Flies is essentially a figment of the littluns' imagination that represents the nameless fears on the island. The littlun with the mulberry-colored birthmark is the first to mention the beastie and refers to it as a 'snake-thing.' The 'snake-thing' alludes to the wicked serpent in the Garden of Eden found in the Old Testament and corresponds to the impending evil that will eventually consume the boys. The older boys initially dismiss the existence of the beastie and claim that the littlun was simply having a night terror. As the novel progresses, the littluns' fear increases and they have trouble sleeping. They claim that the beastie comes out of the sea and also mention that they dream about it living in the trees. Ralph and Piggy are concerned about the littluns' well-being while Jack criticizes and makes fun of them for believing in the beastie. Although the beastie is not a tangible being, it represents all of the fears, both physical and psychological, that are found on an island without adult supervision and the comforts of home. Stranded on a deserted island, the littluns are afraid and traumatized. The beastie conceptually encompasses their fears and symbolically represents the wickedness inherent in each of them.