In the 'Harry Potter Pranks Everyone' fanfiction, there could be some hilarious pranks. For example, a student might use a charm to make the Great Hall's ceiling show embarrassing memories of the teachers. Another prank could be to magically swap everyone's voices, so that when they talk, it comes out as someone else's voice. There could also be a prank where the Hogwarts Express gets diverted to a completely different location, and the students end up in a strange magical place full of odd creatures and unexpected challenges.
Typically, Harry is one of the main ones. He has a knack for getting into and out of trouble with his pranks. Hermione might also be involved in some pranks in a more strategic way, using her vast knowledge of magic to create unique and elaborate pranks. And of course, the Weasley twins are almost always at the center of the most elaborate and chaotic pranks in the fanfiction.
A really funny prank could be where a student's quill is jinxed to write only in limericks. So when they're trying to take notes in class, instead of normal writing, it comes out as comical rhymes. This can be a source of great embarrassment, especially if they don't notice right away. Also, pranks with vanishing ink on important parchments are quite common in fanfiction. The victim thinks they've written important information, but it all disappears, leaving them frustrated and others amused.
One prank could be Harry using magic to make all of Dudley's clothes two sizes too small overnight. Another might be making the Dursleys' living room furniture float whenever they try to sit down. And he could also use magic to make the food on their table turn into slugs when they're about to eat.
One great 'Harry Potter Pranks' fanfic is 'The Prankster's Legacy'. It shows the Weasley twins' pranks in a whole new light, with detailed descriptions of their elaborate set - ups. Another good one is 'Pranks at Hogwarts' which focuses on different students' attempts at pranks throughout the school year. And 'A Prank - Filled Adventure' is also quite interesting as it follows a group of students who form a prank club and their misadventures.
There could be a fanfiction where Hermione comes up with a brilliant prank. She uses a spell to make Umbridge's parchment write out all the unjust rules she has made instead of whatever Umbridge is trying to write. Every time Umbridge tries to write a memo or a note, the parchment just keeps repeating things like 'No groups larger than three' and 'No fun allowed' over and over again, driving her mad.
One prank that's quite common in fanfiction is when students bewitch the stairs to move in unexpected ways, like turning into slides or leading to wrong floors. This causes a lot of confusion, especially for first - years. Also, there are pranks where students use transfiguration to change the appearance of teachers' desks into something ridiculous, like a giant cake or a pool of slime.
Well, in some fanfictions, there are pranks like magically changing the taste of the food in the Great Hall. So, instead of delicious pudding, it turns into something like stinky socks. Also, pranks with brooms are popular. For example, some students might charm the Slytherin team's brooms to suddenly start flying backwards during a Quidditch match. And then there are pranks with spells that make a person's voice change randomly, which can lead to some really funny situations in the hallways.
The Weasley twins, Fred and George, are the most likely characters to pull pranks. They have a natural inclination towards mischief and are always coming up with new and creative ways to play jokes on their classmates and teachers. Their inventions, like the Skiving Snackboxes, are often used in pranks.
Probably not as popular as the regular positive or canon - compliant Harry Potter fanfiction. Most fans love the characters and the world, so bashing everyone might not appeal to the general fanbase.