One of the first things that new Harry Potter fans learn about the series (maybe the very first, in fact) is that those dastardly Dursleys are some of the most unpleasant, judgemental, and snobbish people you could ever meet in a British suburb. Vernon and Petunia Dursley have a great fear and loathing of magic, which extends to Petunia’s own sister and brother-in-law, Lily and James Potter.

RELATED: Harry Potter: 10 Things About Dudley Dursley Left Out Of The Movies

On losing his parents, Harry Potter is brought to live with Vernon and Petunia, who extend that fear and hatred to the boy and instill it in their own son, Dudley. As we know, this leads to years of bullying, bickering, and cruelty between the two boys. Harry is often seen as the victim, but he was terrible to his cousin at times too. Let’s take a look at some of the worst things Harry and Dudley did to each other.

DUDLEY: Bullying Harry At School

In a world that tends to be associated with witches, wizards, giants, werewolves, centaurs and all manner of other fantastical creatures, the Harry Potter series remains very down to Earth. Before all of the brilliant magical nonsense begins, J.K. Rowling goes to great lengths to explain the very real and relatable torment Harry suffers at Dudley’s hands at school.

The novel Harry Potter and the Sorcerer’s Stone details Dudley and his friends’ love of ‘Harry hunting’ at school, and explains that Harry’s glasses are taped together because he’s been punched in the face by the bullies so many times.

HARRY: The Snake Incident

Now, granted, this wasn’t exactly Harry’s fault. Magic often leaks out of underaged wizards and witches against their wills, as a result of strong emotions. When it comes to cruel things to do to your cousin, though, trapping them in the boa constrictor/Burmese python’s enclosure at the zoo is just a shade above the usual silly family practical jokes.

The movie made this little scene seem much more dramatic, not to mention traumatic on poor old Dudley’s part. Still, nobody was hurt, and we like to imagine the snake actually did find its way to Brazil eventually.

DUDLEY: Taunts About Harry’s Isolation

The time between the end of Harry’s first year at his beloved Hogwarts and the start of his second was super difficult for him. In the beginning of Harry Potter and the Chamber of Secrets, he’s being hounded by a House Elf named Dobby, who knows that terrible things are going to happen at Hogwarts that year and wants to ensure Harry stays at home.

RELATED: Harry Potter IRL: 10 Similarities Between Hogwarts & UK Boarding Schools

Dobby messes with Harry in all kinds of ways, including hiding the letters he gets from his friends to make Harry think they’ve forgotten him. In the novel, Dudley, knowing all about Harry’s intense isolation (which he’s suffered throughout his life to date), jumps on the opportunity to taunt him about the fact that he has (seemingly) received nothing for his birthday. Coming from a boy who threw a famous tantrum because he only had 36 birthday presents, this must really sting.

HARRY: Taunting Dudley With Magic

So, yes. That was a very low blow on Dudley’s part, reveling in the fact that it looked as though Harry had no friends (he didn’t at their last school, because everyone was afraid of Dudley and knew he hated Harry). He’s not the only one capable of this sort of thing, though.

Harry knows that the Dursleys are terrified of magic, and found the pig’s tail that Hagrid gave Dudley when they first met hilarious. Traumatic as this experience surely was for Dudley, Harry gleefully pretended to curse his cousin on several occasions, for the pleasure of watching his dashing horrified from the room.

DUDLEY: Refusing To Give Harry His Second Bedroom

With the Dursleys being notoriously snobbish social climbers, it’s no surprise that their only child would have a ‘second bedroom,’ a sort of overflow for all the excess possessions that have been lavished upon him. Harry, meanwhile, is left to sleep in the cupboard under the stairs.

Before long, Vernon and Petunia deem it necessary for Harry to take Dudley’s second bedroom as his own. Dudley, with absolutely no need of it, throws an incredible tantrum at the idea. In the first novel, J.K. Rowling describes his reaction to the news: “He’d screamed, whacked his father with his Smelting stick, been sick on purpose, kicked his mother, and thrown his tortoise through the greenhouse roof, and he still didn’t have his room back.”

HARRY: Manipulating Dudley’s Lack Of Intelligence

This is one element of Harry and Dudley’s relationship that you’d need to have read the books to really appreciate. Daniel Radcliffe’s Harry Potter is, many fans say, much less snarky and sassy than the Harry Potter of the books, who was more inclined to cruelly manipulate and make fun of Dudley, who isn’t an intelligent as he is.

He compares Grawp (Hagrid’s giant half-brother) and his struggles to learn English to Dudley. He makes sarcastic jokes to his face and then hurries away before Dudley has processed them. As with the taunts about magic, these are very cheap shots.

DUDLEY: Bullying Harry For His Grief Over Cedric Diggory’s Death

Harry clutching Cedric's body in Harry Potter

The long-suffering Hufflepuff house just didn’t deserve this. The tragic death of Cedric Diggory at the end of Harry Potter and the Goblet of Fire marked the loss of the house’s most notable student. It also, naturally, traumatized Harry to his very core, after his narrow escape from Voldemort’s clutches.

RELATED: Fantastic Beasts: 10 Newt Scamander Quotes That Inspire Hufflepuffs

The Dursleys, of course, didn’t know the full story of what had happened at that graveyard. Nevertheless, Dudley ramped up his program of taunting Harry afterwards, as his cousin had been experiencing nightmares and talking in his sleep. This served as perfect insult fodder for him.

HARRY: The Dementor Attack

A Dementor attacks Dudley in Harry Potter

Well, strictly speaking, the Dementor attack in Little Whinging wasn’t strictly Harry’s fault. They had been sent after him by none other than Dolores Umbridge (think of her as a female Voldemort with less charm and lots of pink cardigans/cat portraits). Nevertheless, the terrified Dudley thought that Harry was casting some kind of spell on him and blamed him for the ordeal.

Interestingly, though, this moment changed Dudley. Under the influence of the Dementor’s powers, he finally recognized how cruelly he had been behaving and was grateful to Harry for saving his life. In their adult lives, the two would share a civil relationship and their children would play together.

DUDLEY: Bringing His Gang To The House

Dudley Dursley standing in front of his gang of friends in Harry Potter and the Order of the Phoenix.

As we know, then, Dudley seemed to make it his mission in life to taunt, aggravate and generally punish Harry for existing whenever he could. Before starting Hogwarts, Harry had attended the same school as his Dudley, who would bully him every day alongside his ruthless gang.

During that last school holiday before he started attending Smeltings, though, Dudley’s vicious cronies came to the house every day. Vernon and Petunia treated him badly enough at home, without his school tormenters following him there!

HARRY: A Bully In His Own Way

In short, the volatile relationship between Harry and Dudley has always been marked by a constant battle of brain versus brawn. Harry is unable to challenge his cousin physically, leaving him with only two weapons: his wits and the threat of magic.

While Harry isn’t allowed to perform magic outside of Hogwarts while underage, the Dursleys don’t learn this until later. In the meantime,  Harry threatened his cousin just as much as Dudley threatened him; only with his wand and insults instead of his fists.

NEXT: Harry Potter: The 10 Worst Things Petunia Dursley Did To Harry, Ranked