The world of Harry Potter is full of complex characters. So complex and divisive are some of these characters, that many fans still have yet to come to a complete agreement on their attributes or status in the fandom.
Snape is without a doubt one of those characters. Love him or hate him, you've got to admit that Snape did some pretty horrible things in his time at Hogwarts. Perhaps some of his worst behavior was directed at the students. These were children who did not earn or deserve his hate, and they had no way to truly defend themselves against his barbs.
As such, we feel compelled to list the ten worst things Snape did to his young students.
10 Favored The Slytherins Over Most of the Student Body
Let's start with the most obvious example. Snape constantly and consistently favored his own house, Slytherin, over the rest of the Hogwarts students. That included everything from giving (or taking) house points, to whose side he took in a disturbance. This even went as far as to what sort of punishments he handed out. Or in the case of the Slytherins, what punishments he refused to hand out.
The bias was extremely unfair, for obvious reasons. Additionally, it created a barrier for any student not in Slytherin who wanted to learn about potions. We don't know for sure how many careers require the skill...but it is concerning nonetheless.
Our second example comes from the time when Snape was a student. When he was young, Snape was very much a fan of Voldemort and the Dark Arts. It's not something he entirely lost, either. He took a lot of Voldemort's policies to heart, including blood purity.
He even called his best (and only) friend a Mudblood — the most hurtful term you can think of. And it came to him so quickly that you know it had crossed his mind once or twice before. Thus, we're concerned about how he feels about his students. Mainly, less "pure" students. After all, Snape is the head of Slytherin — a house known for its purity — and he favors them so much it's hard to tell how far it all goes.
8 Insufferable Know-It-All
One of Snape's favorite targets was the brilliant Hermione Granger. Now, we don't know his motives here, but we can guess. It probably had at least a little bit to do with her friendship with Harry Potter. Additionally, her brilliance made it harder to favor the Slytherins.
No matter the cause, it's clear that Snape loathed that Hermione was so smart and so willing to answer any and all questions during class. He even called her an 'insufferable know-it-all" at one point, even though she was literally doing nothing more than answering his questions.
7 Bullied The Boy He Was Protecting
No matter how you look at it, it's clear that Snape loved loathing Harry Potter. Harry, the boy he had promised to do his best to keep alive. Harry, the son of the woman he loved. And yet, because Harry looked like his father, the man Snape loathed, he was more than willing to torture the kid.
Even Snape's first words to Harry were snide and cruel. He made no attempt to see the good side of Harry, and instead actively enjoyed picking on and belittling him. Perhaps because it was something he couldn't do to the late James Potter.
6 Stopped Teaching Harry
This one might not technically fall under bullying, but think about it. Snape had promised Dumbledore that he would train Harry to close his mind to Voldemort's. And yet the second it became hard, (read: the moment Harry dove into Snape's most embarrassing memories) he refused to teach Harry ever again.
Given what was at stake, this is pretty horrible. We all know that what Harry did was wrong, but Snape was the adult in this situation. He should have acted like one. Getting angry is one thing — but what he did went too far. The consequences were disastrous.
5 His Targeted Hatred of Neville Longbottom
Perhaps the worst thing Snape did over the course of the novels was torment Neville. Snape seemed to truly love hating the boy, and doing everything he could to make him miserable. It was inhuman how much Snape enjoyed doing it.
He scared Neville so much that his Boggart turned into Snape — a true sign that Snape was the thing that Neville feared most in life. Think about that for a moment. This was no idle fear or intimidation. This went so much deeper and was so much more insidious than that.
There are so many examples of his behavior towards Neville they need to be included separately (see below). But as a whole, Snape tormented Neville every single Potions class, which made Neville's potions inevitably turn out worse. It was almost like Snape planned it.
4 Public Humiliation
Snape didn't just torture Neville within the confines of his classroom. On at least two occasion,s Snape took it upon himself to belittle Neville in front of a crowd, including at least one other professor. The first time was during Dueling Club, where he mocked Neville's lack of skills to Lockhart.
The second time was in front of the rest of the Defense Against the Dark Arts class, and once again he was "warning" the professor of Neville's incompetence. Thankfully, Lupin ignored the barb and instead did what he could to raise Neville's spirits in a subtle manner.
3 “I See No Difference”
As mentioned, Snape loved hating on several Gryffindor characters, including Hermione Granger. But Snape took his mocking too far. No teacher should ever make fun of a student for the way they look. Especially not when those students are teenagers and thus, particularly vulnerable. Yet that's exactly what he did.
When Hermione was hit with an engorgement spell, her buck teeth began to rapidly grow, quickly becoming too large for her face. Snape stated that he "saw no difference." This was cruel and completely inappropriate.
2 All The Times He Tried To Get Harry Expelled
Let us not forget all of the times Snape called for harsher punishment in response to Harry's actions, even when it wasn't his place to say so — that would be either the Headmaster's or Head of House's job. On more than one occasion, Snape threatened Harry with expulsion, even though he didn't have any right to do so.
We're not sure if this was all due to his hatred of Harry — or if he really did think that Harry would be safer back at home. But we don't really buy that the latter is possible. So yeah, it's probably just hatred. Which is all sorts of messed up. Remember that expulsion would result in Harry losing his wand and thus, access to magic.
1 The Time He Wanted to Poison Trevor
We've already talked about how Snape hated Neville, and how he tortured him the most out of all of the characters. And even by Snape standards, this last action went too far.
He once threatened to feed a potion Neville made to Trevor, his toad. If the potion was made properly, it would turn Trevor into a toadstool. If made improperly, it would poison Trevor. Given that Snape expected the potion to be wrong, that means that he was fully planning on poisoning Neville's beloved pet. In fact, when Trevor shrunk instead of perished, Snape took house points away from Gryffindor. Can you imagine how that must have felt for Neville? Or how horrible you'd have to be, in order to think that sort of behavior is okay?