Who is The Peddler from The Land I Lost: Adventures of a Boy in Vietnam and what is their importance?

The peddler came to town boasting that he could train a group of monkeys in a short amount of time. His gruesome technique involved cutting the head off the group's unruly leader, to show the other monkeys what would happen if they did not do as he instructed. Terrorized, the monkeys quickly fell in line and did what they were ordered to do.