What does the pigs head-the "lord of the flies"-tell Simon?

From the text:

"You are a silly little boy," said the Lord of the Flies, "just an ignorant, silly little boy."

Simon moved his swollen tongue but said nothing.

"Don't you agree?" said the Lord of the Flies. "Aren't you just a silly little boy?"

Simon answered him in the same silent voice.

"Well then," said the Lord of the Flies, "you'd better run off and play with the others. They think you're batty. You don't want Ralph to think you're batty, do you? You like Ralph a lot, don't you? And Piggy, and Jack?"

Simon's head was tilted slightly up. His eyes could not break away and the Lord of the Flies hung in space before him.

"What are you doing out here all alone? Aren't you afraid of me?"

Simon shook.

"There isn't anyone to help you. Only me. And I'm the Beast."

Simon's mouth labored, brought forth audible words. "Pig's head on a stick."

"Fancy thinking the Beast was something you could hunt and kill!" said the head.

For a moment or two the forest and all the other dimly appreciated places echoed with the parody of laughter.

"You knew, didn't you? I'm part of you? Close, close, close! I'm the reason why it's no go? Why things are what they are?" The laughter shivered again. "Come now," said the Lord of the Flies. "Get back to the others and we'll forget the whole thing."