The beast has several names already in the book Lord of the Flies. It is initially referred to as a snake-thing or beastie. Later during his internalised conversation the beast is named as the Lord of the Flies. Finally the real nature of the beast is revealed as the darkness in the hearts of men.
In Lord of the Flies there is technically no physcial beast. "The Beast" is a symbol for something greater i.e our inner savergery. Golding uses the beast as only a symbol which the boys seem to reconize even more with their desent into savergery