Who is Peter from Welcome to the Monkey House and what is their importance?

Peter is the oldest orphan. He is a very bitter 14-year-old. He remembers his family and the war. He also remembers having more food and a real home. He seems to take out his frustration and sadness on other kids. He lies to Joe about Joe's parents and tries to pick fights with him. He also refuses to believe that Joe really met his dad.