Two real-life quidditch teams have moved to change the name of the game to "quadball" in order to distance themselves from Harry Potter and the controversy surrounding J.K. Rowling. Quidditch matches in the books and movies were driven by the long-standing rivalry between the houses of Gryffindor and Slytherin and they are some of the most intense events in Hogwarts. Gryffindors believe Slytherins are absolutely evil, whereas Slytherins think Gryffindors are pathetic in their heroism and chivalry.
However, the two houses have more in common than they would like to believe. They are both extremely determined and resourceful leaders, so Gryffindor's recklessness and thrill-seeking personality can soon turn into Slytherin's arrogance, greed, and manipulative behavior.
Peter Pettigrew
Pettigrew: "What would you have done? What would you have done?"
Sirius: "I Would Have Died!"
When Sirius and Remus confront Peter about betraying James and Lily Potter, their best friends, Peter desperately tries to defend himself by assuming that everyone in his place would have done the same thing.
However, as Sirius expresses, not everyone would have preferred to keep on living betraying their friends. This is a characteristically Slytherin trait, choosing one's self over anyone else, no matter the circumstance, even if it means killing an innocent baby.
Fred And George Weasley
Fred and George: "Ten Galleons."
Full quote: "Ron: "How Much For this?" / Fred and George: "Five Galleons." / Ron: "How Much For Me?" / Fred and George: "Five Galleons." / Ron: "I'm Your Brother."
When Harry, Ron, and Hermione visit Fred and George at their recently opened and very successful store, Ron asks his brother to give him a family discount. However, the Weasley twins are ruthless entrepreneurs who don't make exceptions.
In one of Fred and George's funniest quotes from the series, the twin brothers perfectly portray the ambition and greediness of a Slytherin. Most of the members of this house are very wealthy, and they didn't accumulate that money by being nice to others.
Ginny Weasley
"I Can't See No Gas."
"That's Because It's Colorless, But If You Want To Walk Through It, Carry On, Then We'll Have Your Body As Proof For The Next Idiot Who Didn't Believe Us."
As one of Harry's biggest allies, Ginny makes sure no one discovers him while he's trying to communicate with Sirius to make sure Voldemort didn't kidnap him. For this, Ginny comes up with the lie that there's a poisonous gas in the hall, and she even gets cocky about it.
Ginny's ability to lie on the spot so cunningly is definitely not a Gryffindor trait. Whereas the Gryffindors are supposed to be noble and chivalrous, the Slytherins are more the clever and resourceful types, adjectives that Ginny embodies to perfection.
Harry Potter
“Not As Stupid As You Look, Are You, Dud? But I S’pose If You Were, You Wouldn’t Be Able To Walk And Talk At The Same Time...”
When Harry runs into his cousin Dudley, he starts taunting him with witty and sarcastic remarks, taking advantage of the fact that Dudley is afraid of Harry's magic.
Even though Dudley has been a terrible cousin to Harry most of his life, Harry abuses his powerful position to get back at him, which is very much a Slytherin attitude. This quote even sounds like something Draco Malfoy would say, and it proves Harry could definitely be a Slytherin.
Hermione Granger
Hermione: "Oh, All Right Then, I Did It. But You Should Have Heard The Way He Was Talking About Ron And Ginny ... You Wouldn’t Have Wanted Someone Like That On The Team."
When Ron is trying out for the goalkeeper position in the Gryffindor Quidditch team, his anxiety gets the best of him, so he has a hard time defeating Cormac McLaggen, an arrogant but talented Gryffindor who is also trying out.
Hermione is particularly known for her respect for rules. However, in the wake of Ron losing his Quidditch position, she abandons all of her principles. It's even worse considering she's a Prefect. Bending rules to benefit her own agenda while abusing her position of power is very much what any Slytherin would have done in that situation.
Oliver Wood
“Bad News, Harry. I've Just Been To See Professor McGonagall About The Firebolt. She ... Seemed To Think I Cared More About Winning The Cup Than I Do About Staying Alive. Just Because I Told Her I Didn't Care If It Threw You Off, As Long As You Caught The Snitch First.”
When Harry receives a Firebolt during his third year at Hogwarts, his professors believe the broom may be cursed, and they won't let him use it. Wood tries to intervene for him, but with no success.
Oliver Wood is usually a nice person, but he's ruthless in the Quidditch field. He will do everything in his power to achieve victory, even if it means killing himself or one of his teammates in the process. This sort of 'the means justifies the end' kind of philosophy could have easily landed Oliver in Slytherin.
Fred Weasley
“An Age Line! Well, That Should Be Fooled By An Aging Potion, Shouldn’t It? And Once Your Name’s In That Goblet, You’re Laughing — It Can’t Tell Whether You’re seventeen Or Not!”
During Harry's fourth year at Hogwarts, Dumbledore announces the Triwizard Tournament, and the Weasley twins are determined to get the thousand galleons prize.
Even if breaking the rules is a key component of Gryffindor's personality, doing so to earn fame and riches is more alongside Slytherin's core traits. Fred and George tend to be resourceful and determined to achieve their objectives, all of which perfectly describes the serpent house.
Ron Weasley
“She’s Already Told Us All Dumbledore’s Letting You Enter. A Thousand Galleons Prize Money, Eh? And You Don’t Have To Do End-Of-Year Tests Either...”
One of Ron's worse fears is not being as successful as his friends and family, and when Harry's name is announced by the Goblet of Fire, he can't help to be deeply jealous. During most of the school year, Ron even stopped talking to Harry, angry at him for once again receiving all the attention.
Gryffindors love the spotlight, that's why they're always in the middle of adventures. But being jealous of a friend for being successful and abandoning him during one of the most stressful moments of his life, it's not exactly chivalrous and loyal. Although, usually, Ron is a great friend, during this time he acted more like a Slytherin.
James Potter
James: “I Will If You Go Out With Me, Evans. Go on ... Go Out With Me, And I’ll Never Lay A Wand On Old Snivelly Again.”
In spite of James Potter being one of the most heroic characters in the books, when he was a student at Hogwarts he was a bully. He used to be mean to Snape without having a reason, and he continually insisted on Lily going out with him, even when the girl clearly disliked him. It may be an unpopular opinion, but probably James and Lily shouldn't have been together.
When James tries to blackmail Lily into going out with him by offering her to stop bothering Snape, he's being manipulative and arrogant, traits that are commonly found in the Slytherin house. However, James eventually grows up and becomes a good husband to Lily and father to Harry.
Sirius Black
Sirius: "I Don’t Need To Look At That Rubbish, I Know It All.”
In one of Snape's school memories, Remus asks Sirius to help him study for one of their O.W.L.s, but Sirius replies that he doesn't need to study because he already knows it all.
Just like his best friend, James, Sirius was a bit arrogant during his school years. Even though he believed to be better than the Black family, he displayed some of their most Slythering attributes, such as thinking himself better than anyone else, muggles and wizards alike.