A Bludger is a round, jet black ball, made of iron, and is used in the wizarding sport of Quidditch. It is ten inches in diameter. There are two Bludgers used in every match, which are bewitched to fly around and try to knock the players off of their brooms. It is the Beater's job to protect their teammates from the Bludgers and at the same time aim them towards the opposing players.