The boys first steps to savagness was when they killed the littlen by settting a forest fire.
The next step into savagness was when Jack’s hunters let the fire go out. Unfortunately a ship passed the island without seeing any smoke
When Jack and his Hunters kill a pig and leave the skull for the "beast", The start the beginning of the end of their decent to savagry
In a dance of blood lust, the boys attack Simon, thinking he is the beast and kills him.
Representing pure anarchy, Roger pushes a bolder at Piggy, forcing him off the cliff into the water.
In the end of the story the boys are at their most savage. They chase Ralph around the island wanting to kill him and put his head on a stake. Ralph is saved by a passing ship who saw the smoke from the forest fire.