Goyle is one of Draco's two stupid henchmen. When Harry and Ron take Polyjuice Potion to turn into Crabbe and Goyle, we get some insight into the relationships between Draco and his two hangers-on. Draco basically just prattles on in front of them without really expecting them to talk or contribute much. Though, he does want them to laugh on cue. When he shows them the Daily Prophet article about Mr. Weasley's fine for his secret flying car, Malfoy says impatiently, "Well? […] Don't you think it's funny?" (12.164). He mocks Goyle ["Honestly, if you were any slower, you'd be going backward" (12.183)] without caring about his feelings. Basically, Draco is a terrible friend. So why do Crabbe and Goyle choose to spend all their time with Draco? What's in it for them?