Throughout the Harry Potter series, the gentle half-giant Rubeus Hagrid is known as many things. He's a father-like protector of Harry, the Hogwarts groundskeeper, the Keeper of the Keys, a Care of Magical Creatures teacher, and, to those who believe in the Hagrid Death Eater theory, an avid follower of Lord Voldemort. Although Hagrid is one of the most memorable and adored Harry Potter characters, Reddit user /u/Whoofph dives deep into the pages of the original seven Harry Potter books to determine whether the beloved Hagrid is a Death Eater or not. According to their research, all signs point to yes.
Hagrid might act suspiciously at times, with his bumbling mannerisms and strange living habits - but is Hagrid a Death Eater? /u/Whoofph's theory is that Hagrid is actually putting up a large facade, spending the entire saga acting as a conspiring agent of the dark arts, benefiting the success of He-Who-Must-Not-Be-Named until the bitter end. Remember, Hagrid fans, it's just a theory, and only one theory.
Hagrid's Magical Abilities Are Used Only By Extraordinary Witches And Wizards, Including Death Eaters
Immediately upon his arrival, Hagrid is seen using extremely advanced magic - with a broken wand. In Harry Potter and the Sorcerer's Stone, Hagrid uses a form of fast-travel magic to get back and forth to Harry. Hagrid is able to use the magic with great efficiency, even though he was expelled from Hogwarts in his third year. Hagrid tells Harry he "flew" to get him, and the only other characters who fly in the books (on something other than a broomstick or thestral, which Hagrid says can't hold his weight) are Voldemort and Snape.
Also, the transfiguration spell Hagrid uses to give Dudley Dursley a pig's tail should be way out of his league, because human transfiguration is taught only in sixth-year N.E.W.T.-level classes at Hogwarts.
Hagrid also does these spells nonverbally, another advanced wizard skill.
Hagrid Has No Empathy Toward Muggles And Torments Them For His Personal Pleasure
In Harry Potter and the Sorcerer’s Stone, Hagrid has no qualms about committing serious acts of cruelty toward Muggles. Tossing aside all wizarding laws, especially the Muggle Protection Act, he uses a broken wand to cast a hostile spell on Dudley Dursley, causing the Muggle child to sprout a curly pig's tail in the center of his bum.
The tail must be removed surgically, and causes Dudley extreme fear and pain.
It's Extremely Easy For Hagrid To Lure Harry Straight To Voldemort
Harry is highly trusting of Hagrid, making it easy for him to bring Harry straight into the hands of Voldemort. In Harry Potter and the Sorcerer's Stone, Hagrid takes Harry to Diagon Alley not only to stock up on school supplies, but to also meet Professor Quirrell, Voldemort's servant who is concealing the Dark Lord in his own body.
Hagrid is also responsible for giving the kids detention, during which he takes them into the Forbidden Forest and sends Harry on a pathway that leads him directly into the hands of Voldemort. Hagrid also pushes the trio into seeking out the Sorcerer's Stone, filling them with information about its existence and leading them back to Voldemort.
Hagrid Makes Sure Voldemort Has Constant Watch Over Secret Affairs
From the start of Harry Potter and the Sorcerer's Stone, Hagrid provides a constant stream of information for Voldemort, giving the dark wizard everything he needs to stalk Harry and his companions' whereabouts. For Harry's birthday, Hagrid buys him the snowy-white owl named Hedwig, who is easy to spot and track, providing a way for Voldemort to find out where Harry chooses to hide.
Hagrid could also be the reason Voldemort knows where the Sorcerer's Stone is. Only Hagrid and Dumbledore know it is stashed in the depths of Gringotts, and Dumbledore is the least likely to leak such sensitive information to dark wizards. Hagrid might also be responsible for Voldemort easily maneuvering his way through Hogwarts protections, a simple task for someone who has learned the castle's magical secrets.