In all of the Harry Potter universe, there is no group quite as universally distrusted and reviled as Slytherin house, which has produced some of the most notorious villains in the history of fantasy, including Lord Voldemort himself.
However, while the house is certainly known for its ethos of ambition and the pursuit of power at any cost, there have been a number of characters, even some of the most villainous, who have shown that the house is not quite as evil as it has been made out to be and that its members can actually do good when the need arises.
Snape’s Love For Lily
Snape is arguably the best and most complicated character in the Harry Potter universe, and though he immediately takes a dislike to Harry and makes his life miserable, he also shows that he is capable of goodness.
In particular, his love for Harry’s mother, Lily, is one of his most remarkable storylines, and the fact that he stays in love with her – even going so far as to adopt her Patronus as his own – suggests that his membership in Slytherin wasn’t a full obstruction of his ability to be a good person. It is also one of the saddest things about Snape in Harry Potter.
When Narcissa Saved Harry
Of all of the wizarding families that appear in the books and the movies, there are few with as bad a reputation as the Malfoys, who view everyone, including Harry, with contempt.
However, there are times when they show that they are fully-realized and complex characters in their own right, most notably when Narcissa lies to Voldemort about whether or not Harry has been killed. It’s an extraordinary moment of humanity, and her actions show why the Malfoys and Slytherins are misunderstood (if nothing else, it shows that Narcissa is a mother, first and foremost, and a good one, deep down).
When Draco Couldn’t Kill Dumbledore
There are many villains that emerge during the course of Harry Potter, and Draco is one of the most notable. While he does many awful things during the course of the story, including getting ensnared in Voldemort’s return, the truth is that Draco Malfoy isn’t nearly as bad or as evil as he would like others to believe.
This can be most clearly observed when he finds himself unable to kill Dumbledore. It’s a crisis of conscience, and it demonstrates more clearly than any of his actions that there is good in him, after all.
When Snape Protected Students As Headmaster
For most of the final book and movie, it seemed like Snape had fully bought into Voldemort’s return and that he had been working for him all along.
It is subsequently revealed, however, that in truth, he was using his position as Headmaster of Hogwarts to protect the students under his care, and that without his constantly running interference that life would have been very difficult, if not deadly, for those who continued their studies at the school after Voldemort rose to power.
When The Malfoys Retreated From The Battle Of Hogwarts
Narcissa’s lying to Voldemort about whether Harry is dead isn’t the only moment where the Malfoys show that there is more to them than meets the eye. Most notably, they decide to retreat from the Battle of Hogwarts rather than fully engage in the battle.
It’s a profound moment for them, especially since there’s every possibility that their master might emerge victoriously and they would then be punished for their failure. For the Malfoys, however, their family ultimately matters more than simple power and conquest.
When Andromeda Tonks Married A Muggle And Worked With The Order
One of the hallmarks of Slytherin is its contempt for those who are Muggle-born, and many of the proudest and purest families are sorted into that house and adopt this attitude. One notable exception is Andromeda Tonks, who not only married a Muggle but also worked with the Order, as did her daughter, Nymphadora Tonks.
As with so many of the other exceptional Slytherins, this demonstrates that there are members of Slytherin who are both willing and able to work against the dominant attitude and that they shouldn’t be so easily written off.
When Slughorn Helped Harry Discover The Truth About Horcruxes
Jim Broadbent has been in many great movies, and it’s arguable that Horace Slughorn is one of his best roles. Though he is vain and glory-seeking, he ultimately shows that he is more than that and that his membership in Slytherin doesn’t make him a bad guy or a straightforward villain.
Perhaps most importantly, he plays a vital role in Harry’s discovery of the Horcruxes, and it can be argued that without his vital help and his providing Harry one of his most important memories, the secret of Voldermort’s power would have remained undiscovered.
When Leta Lestrange Sacrificed Herself
There are many brave Slytherins in Harry Potter, and arguably, Leta Lestrange is one of the most courageous. Even though she was sorted into Slytherin, she didn’t allow that to keep her from doing her best to fight against the rise of Grindelwald, but even before this, she had shown that she was willing to work closely with the Ministry of Magic.
Most notably, she sacrificed her life to save others. At first glance, this would seem to go against the very ethos of Slytherin, but it shows that its members are capable of sacrifice for those they love.
When Regulus Black Gave His Life Trying to Destroy the Horcruxes
Though Sirius Black is the most important member of his family to appear in the series, it is also true that his brother, Regulus, though largely unseen, is a pivotal character.
Though he is sorted into Slytherin and became a Death Eater, he later became one of those who notably fought against Lord Voldemort and set out to destroy his Horcruxes. More than anything else, this demonstrates that the members of Slytherin have it in themselves to do the right thing, even if that means going against one of their own.
When Merlin Was An Advocate For Muggle Rights
There have been many famous and powerful wizards who have been a member of Slytherin house, but arguably, one of the most famous is Merlin, the adviser to King Arthur himself.
Though he was sorted into the Hogwarts house most well-known for its antipathy toward Muggles, it is revealed that he was actually an advocate for Muggle rights, suggesting that, as is the case with Gryffindor, Ravenclaw, and Hufflepuff, just because one is sorted into Slytherin, doesn’t mean that one necessarily has to be a Muggle-hating villain.