Mrs Norris's Revenge
First things first, Mrs Norris was the realist. Much to her dismay the witches and wizards of Hogwarts school of witchcraft and wizardry didn't seem to think so. Her only friend was Argus Filch - that was enough to make anyone cry (even Voldemort).
It wasn't just the students who made her feline blood boil on a daily basis. They had to bring their filthy pets with them. The one cat Mrs Norris could not stand was Crooshanks. He was so ugly that if he walked into Gringotts Wizarding Bank, they'd give him a job application.
One day Mrs Norris went for a leisurely stroll round campus whilst Filchy cried alone in his cupboard about being a squib. She was enjoying the glorious sunshine near the lake when Crooshanks had to swagger over and ruin her entire day.
One thing that everyone should know about Mrs Norris is that she's an independent sassy feline who don't need no man. Trying to tell Crooshanks this proved to be rather difficult. Just as she thought he had finally got the message that she wasn't interested Crooshanks said:
"Does this rag smell like Choloroform to you?"
Darkness.
The next thing Mrs Norris remembers after having Crooshanks's fat ginger paw in her face, is waking up in the Gryffindor common room. How he had managed to carry her all that way she will never know and she didn't want to ask.
Crooshanks sat by her with a creepy smile etched across his blubbery face.
"If I could rearrange the alphabet I'd put u and I together".
Great. More terrible chat up lines. At least that one didn't make her unconscious.
"Oh but Crooshanks I like it just the way it is…N and O."
The smile vanished from his face and he looked like he wanted to cry.
"But we could fight the Death Eaters together and be a kickass power couple."
There was a million and one things Mrs Norris would rather do than be in a relationship with Crooshanks. One of those things included having to drink the Filchinator's bath water.
Before Mrs Norris could say anything else, Hermione Granger walked in. She saw the rag of chloroform and automatically presumed it was Mrs Norris who used it on Crooshanks. It was not wonder Hermione had such a great figure, she must have burned so many calories jumping to conclusions. If she was the smartest witch her age that really said a lot about the intelligence of the other pupils.
Hermione grabbed Mrs Norris by the scruff of her neck and dropped kicked her down one of the moving stair cases. She was aware that nobody realised her self-worth but never in her life had she been so humiliated. As pupils charged back to their dormitories after their classes they didn't even acknowledge her presence.
As Mrs Norris limped back to Filches cupboard she felt an overwhelming sense of rage she never knew she was capable of feeling. Year after year, witches and wizards came to Hogwarts thinking they were all high and mighty even though most of them struggled to master wingardium-leviosa (a spell which Mrs Norris could do in her sleep)
"Oh there you are Mrs Norris I was starting to get worried about you." Filch sniffled as he opened the door. A devious grin appeared on her face when she had a sudden realisation. First she would take over Hogwarts. Then she would have world domination.