I'm wondering if Crabbe and Goyle were teenage Death Eaters, like Draco Malfoy was.
It's not explicitly confirmed in canon if they were or not, but two canon passages in particular, from Goblet of Fire and Deathly Hallows respectively, keep cropping up for me which imply it might have been a possibility.
‘And here,’ Voldemort moved on to the two largest hooded figures, ‘we have Crabbe ... you will do better this time, will you not, Crabbe? And you, Goyle?’
They bowed clumsily, muttering dully.
‘Yes, master ...’
‘We will, master ...’
Goblet of Fire -- page 565 -- Bloomsbury -- chapter 33, The Death Eaters
Clearly Crabbe and Goyle's fathers were Death Eaters. Being minions of Draco Malfoy, whose father was also Death Eater, would Crabbe and Goyle have wanted to emulate either Draco or their fathers (or both) by following down the same path? J.K. Rowling seems to enjoy the trope in the Harry Potter series of children closely modeling their parents in looks, interests, and destinies.
‘So how come you three aren’t with Voldemort?’ asked Harry.
‘We’re gonna be rewarded,’ said Crabbe: his voice was surprisingly soft for such an enormous person; Harry had hardly ever heard him speak before. Crabbe was smiling like a small child promised a large bag of sweets. ‘We ’ung back, Potter. We decided not to go. Decided to bring you to ’im.’
‘Good plan,’ said Harry in mock admiration. He could not believe that he was this close, and was going to be thwarted by Malfoy, Crabbe and Goyle.
Deathly Hallows -- page 505 -- Bloomsbury -- chapter 31, The Battle of Hogwarts
Crabbe, at least, wanted to physically harm Harry, to essentially facilitate Harry's death by the hand of Voldemort. As well, Crabbe was interested in actually delivering Harry to Voldemort in turn for a reward. It seems to me that Voldemort might have had conversations with Crabbe and Goyle directly, but, Ginny Weasley and Tom Riddle's diary aside, would Voldemort deign to have a conversation with mere students unless there was something in it for him, tangible or strategical?
Crabbe -- again, at least -- used the Cruciatus and Avada Kedavra Curses against Hermione and Harry in the Room of the Requirement. He then goes on to cast Fiendfyre. Goyle is also present and seems to be involved, although J.K. Rowling doesn't detail Goyle as being as excited by engaging in violence as Crabbe was.
So were Crabbe and Goyle more likely bona fide Death Eaters or Voldemort sympathizers who clumsily tried to grab a bit of the action for themselves? Were Crabbe and Goyle Death Eaters?