they killed simon because they believed he was the beast
In the middle of the frenzy in "Lord of the Flies," the boys mistake Simon for the beast and brutally kill him during a chaotic and violent ritual. This mistake highlights the boys' descent into savagery and the breakdown of their society on the island.
Basically that "the beast" isn't something they can hunt or kill but an evil force inherit to the boys. It also tells Simon that he won't be able to escape and he will only find the beast among the other boys. Which comes true when the boys later kill Simon.
The boys mistakenly kill Simon, a member of their group, mistaking him for the beast during a chaotic and frenzied moment. Simon had come down from the mountain, where he had discovered the truth about the supposed beast, but the boys, caught up in their fear and mob mentality, attack and kill him.
I'm pretty sure that's the chapter where the boys mistake him for the "beastie" and they kill him.
Simon and piggy
Basically that "the beast" isn't something they can hunt or kill but an evil force inherit to the boys. It also tells Simon that he won't be able to escape and he will only find the beast among the other boys. Which comes true when the boys later kill Simon.
Simon
Simon and Piggy.
Simon was mistaken for the beast in "Lord of the Flies". He was killed by the other boys during a frenzied tribal dance on the beach.
How is Simon from lord of the flies?
Simon and Piggy
The lord of the flies tells Simon that they cannot escape him, the beast, for it is inside themselves. They are the beast. It also tells him that 'he' is going to have fun, and everyone will kill him.