Like Harry, we spent a lot of time doubting Snape’s loyalty to Dumbledore, but we never once doubted this: the Head of Slytherin house had a cutting remark for every occasion.
Snape in his potions class room from the Order of the Pheonix

Here are 11 times he proved he was the most demanding teacher at Hogwarts...

Snape never suffered fools gladly…

‘Only Muggles talk of “mind-reading”. The mind is not a book, to be opened at will and examined at leisure. Thoughts are not etched on the inside of skulls, to be perused by any invader. The mind is a complex and many-layered thing, Potter – or at least, most minds are.’
Harry Potter and the Order of the Phoenix

However, knowing too much was just as offensive to him

‘That is the second time you have spoken out of turn, Miss Granger,’ said Snape coolly. ‘Five more points from Gryffindor for being an insufferable know-it-all.’
Harry Potter and the Prisoner of Azkaban

He seriously doubted all his students’ abilities…

‘You are here to learn the subtle science and exact art of potion-making … As there is little foolish wand-waving here, many of you will hardly believe this is magic. I don’t expect you will really understand the beauty of the softly simmering cauldron with its shimmering fumes, the delicate power of liquids that creep through human veins, bewitching the mind, ensnaring the senses … I can teach you how to bottle fame, brew glory, even stopper death – if you aren’t as big a bunch of dunderheads as I usually have to teach.’
Harry Potter and the Philosopher’s Stone

He almost always saved his most inspired tongue-lashings for Harry

‘Then you will find yourself easy prey for the Dark Lord!’ said Snape savagely. ‘Fools who wear their hearts proudly on their sleeves, who cannot control their emotions, who wallow in sad memories and allow themselves to be provoked so easily – weak people, in other words – they stand no chance against his powers! He will penetrate your mind with absurd ease, Potter!’
Harry Potter and the Order of the Phoenix

Snape headshot from the Order of the Pheonix

He did not like Harry’s father, James, when they were at school together…

‘How extraordinarily like your father you are, Potter,’ Snape said suddenly, his eyes glinting. ‘He too was exceedingly arrogant. A small amount of talent on the Quidditch pitch made him think he was a cut above the rest of us too, strutting around the place with his friends and admirers ... The resemblance between you is uncanny.’
Harry Potter and the Prisoner of Azkaban

He was never terribly fond of Harry, either

‘You might be labouring under the delusion that the entire wizarding world is impressed with you,’ Snape went on, so quietly that no one else could hear him… ‘but I don't care how many times your picture appears in the papers. To me, Potter, you are nothing but a nasty little boy who considers rules to be beneath him.’
Harry Potter and the Goblet of Fire

Not fond at all…

‘That is just as well, Potter,’ said Snape coldly, ‘because you are neither special nor important, and it is not up to you to find out what the Dark Lord is saying to his Death Eaters.’
Harry Potter and the Order of the Phoenix

He also wasn’t happy about the Weasley boys…

‘Another ten points from Gryffindor. I would expect nothing more sophisticated from you, Ronald Weasley, the boy so solid he cannot Apparate half an inch across a room.’
Harry Potter and the Half-Blood Prince

Snape pushes Harry and Ron's heads down in the Goblet of Fire.

There were times he could be a bit funny. Mean, but funny…

‘Yes, it is easy to see that nearly six years of magical education have not been wasted on you, Potter. Ghosts are transparent.’
Harry Potter and the Half-Blood Prince

Even when he was trying to help

‘Potter, when I want nonsense shouted at me I shall give you a Babbling Beverage. And Crabbe, loosen your hold a little. If Longbottom suffocates it will mean a lot of tedious paperwork and I am afraid I shall have to mention it on your reference if ever you apply for a job.’
Harry Potter and the Order of the Phoenix

It was probably wise to continue to live in heart-stopping fear of him all the same...

‘Moronic though some of this class undoubtedly are, I expect you to scrape an ‘Acceptable’ in your O.W.L., or suffer my... displeasure.’
Harry Potter and the Order of the Phoenix

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