Mason!

Davy is small and skinny - a bit like his namesake, David, a shepherd boy and future king of Isreal, who lived long ago. Mason is a very large boy who is the school bully at Blackton High. Davy is attacked mercilessly for months at school by the bully. Davy likens him to Goliath, the giant Philistine that David fought with a simple sling in the Bible story. When Davy's best friend, Tats, is attacked, the boys decide they have to do something to stop the bully. It proves harder than they think. They realise it can't be done by themselves but that they have to get help from others - including adults. Eventually, Goliath is defeated by Davy but not before he almost loses his life.