Harry Potter and the Half-Blood Prince
Crabbe and Goyle
House: Slytherin, 6th Year
Crabbe and Goyle are Draco's not-too-bright henchmen. In this story, Draco disguises them as young girls (using Polyjuice Potion) so that they can keep watch outside of the Room of Requirement for him. These two bullies always travel together and consider Draco to be their boss, and though Draco uses them, he does not trust them with any important information.