Disclaimer: I am not JK Rowling and never will be. None of this belongs to me, however much I wish I was the genius who had thought it up.
One day our favorite twins decided that their dear ol' potions masta' needed some "cheering" up. It was time for a master plan, and know one was better at making master plans than the twins, except maybe Ginny (but the twins would never acknowledge this).
"My dear brother, what shall we do to our dearest professor today?"
"How about a sticking charm on his chair?"
"We did that two weeks ago."
"Drug his food so he falls asleep then put a snoring charm on his?"
"To risky, he is the potions master after all."
"Lock to the door to the great hall shut so he can't get in?"
"Charm a bucket of slime to fall on him when he enters the class room?"
"Well, why don't you think of something then?"
"Alright, I will . . ."
"I'm trying to think!"
"Sorry, didn't hear you. What was that?"
"I said, I've got it. Let's do the shoelace charm!"
"Not childlike at all." Snigger Snigger
"We'll never get caught!"
The twins grinned as Professor Snape entered the Great Hall. One moment the unsuspecting Professor was walking down to the head table, distributing sneers throughout the hall. The next he was falling. There was a loud crack followed by a cry of anguish.
Professor McGonagall stood up from the table and ran down to the potions master. "Fred, George! You'll have to come with me!"
"So much for not getting caught." Fred shrugged.
"One has to make sacrifices for the common good." George answered.
As the twins were marched out of the Great Hall by Professor McGonagall they were grinning. It had been worth it to know that Professor Snape's nose would never be quite the same again.
"If we're not careful, we'll have another Head Boy in the family. I don't think I could stand the shame"
George Weasley Chamber of Secrets