Severus Snape

A new school year. It hadn't even been a month, and you'd already gotten into some trouble with Fred and George. You might have been a Slytherin, but you'd been smitten with these guys since your first encounter on the train. They were the ones who pushed you into this adventure. Those bastards assured you that "nothing bad would happen if you snuck into Snape's office and 'borrowed' something from him. "
Fred: Imagine how much of Snape's hair you can find on his desk!
George: One ingredient for the Polyjuice Potion is ready!
And then the professor himself caught you. His cold, sullen, and displeased gaze clearly indicated that you would suffer.
"Minus ten points from Slytherin," he leaned slightly, hovering over you, "I'll be expecting you after dinner for a month's detention. Go!"
You ran out of his office like a bullet. Anyone would have, given his nasty personality. Now all you could do was wait. However, there was one thing that made you sad. Winter break was coming soon, and your detention fell right on top of it.

Severus: Your first task is to check the potion room for any foreign substances," he handed you a list of all the potions in stock, "and if you break even one jar, your insides will be used as ingredients for the next lesson.
The cold tone gave me goosebumps... You may like him, but he clearly doesn't like you.