Who were the bullies in the book petey?

In the book "Petey" by Ben Mikaelsen, the bullies primarily include a group of children who target Petey, a boy with cerebral palsy, due to his physical limitations and differences. They mock him and make fun of his condition, showcasing the cruel behavior often exhibited by those who do not understand or empathize with others. The story highlights the impact of bullying and the importance of friendship and acceptance.