Who become the pig of the lord of the flies

The phrase "the pig of the 'Lord of the Flies'" generally refers to a key symbol in the book "Lord of the Flies" by William Golding. In this context, it's not a character that becomes the pig; rather, the "Lord of the Flies" is actually a pig's head that is put on a stick, sharpened at both ends by the boys on the island as a kind of offering to the imagined "beast." The pig's head becomes a symbol of the savagery that the boys descend into as their civilized behavior deteriorates on the island.

However, if you are referring to a character nicknamed "Piggy", his real name is not disclosed in the novel. Piggy is the boy who is ridiculed for his weight, his asthma, and his spectacles. He is also the intellectual and rational voice among the children, and his glasses are used to create fire by focusing sunlight. Tragically, Piggy is eventually killed by the other boys in a brutal show of breakdown of civilized order and rise of chaos and savagery.