It really depends on which part of the book your referring to, but i believe it is the beast that is up there or what they assume to be the beast.
um, ok?
Ralph, Jack, and Simon
Early in the novel Ralph, Jack and Simon climb the mountain to ascertain if they are actually on an island. Later in the book Ralph, Jack and Roger climb the mountain in search of the beast.
Ralph insists that a signal fire must be made so that when his father comes to rescue them on a ship, the men on board will see the smoke and know where to find them. Also, burning things is fun.
Ralph said that a ship could see the smoke from up there and rescue them.
when simon sees the lord of the flies thing his epilepsy happenens and makes him see things hear things and he falls down the hill with a bloody nose from it.
In "Lord of the Flies," the three boys described as the "three blind mice" are Piggy, Ralph, and Jack. They are referred to in this way because they fail to see the dangers and consequences of their actions on the island.
Well, when Ralph is hallucinating he talks to the lord if the flies. While talking to it, it tells him "or else we shall do you? See? Jack and Roger and Maurice and Robert and Bill and Piggy and Ralph. Do you. See?." Meaning that all those people he just named will partake in Simon's death. Which, they did in chapter 9 during the ritual we he stuccoed down from the mountain.
In the very beginning. He wanted to see how many boys had made it off the plane...
Piggy. He has to inventarise the other boy´s names.
Because Ralph doesn't hide his emotions, he expresses them freely. When he is ecstatically happy he stands on his head and when he is angry he loses his temper. Ralph 'wears his heart on his sleeve' for all to see and they know exactly where they stand with him.
Chapter Seven ends with Ralph, Jack and Roger climbing to the top of the mountain, where they see the dead body of the pilot but in the darkness they mistake it for the beast.