Maybe Harry could use a transfiguration spell to turn all of the twins' clothes into something ridiculous, like bright pink tutus. Since they are always the ones playing pranks, it would be a great turn of events. He could do it when they are about to go to a big event at Hogwarts, like a Quidditch match or a school dance.
Harry could use the Marauder's Map to always know where Voldemort is and then set up little magical traps in his path. For example, a puddle that turns into a sticky mess when Voldemort steps in it.
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.
One idea could be the twins inventing a new type of magical prank product that has unexpected effects on Hogwarts. For example, it might make the staircases act even more erratically than normal, causing chaos throughout the school.
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 great fanfiction could be about Harry joining the Weasley twins in their prank - planning adventures at Hogwarts. They might come up with some elaborate schemes to outwit Snape or Filch.
You might like 'The Twins' Unseen World'. This fanfiction takes a different approach to the Weasley twins. It shows their relationship from a more emotional and hidden side. There are parts where they face challenges together and the way they rely on each other is beautifully written. It's a great read for those who love exploring the deeper connection between the two.
One interesting prank could be to magically change the Dark Lord's robes into something ridiculous like a frilly pink dress. It would be a shock to his dignity and his followers' perception of him.
A popular 'Harry Potter and Weasley Twins' fanfiction is 'Pranksters in Peril'. In this one, the twins find themselves in a dangerous situation after one of their pranks goes wrong in a big way. It's exciting to read as they use their wits and their knowledge of magic to get out of trouble. Another one is 'Weasley Twins and the Time - Turner'. This fanfic plays with the idea of the twins getting hold of a Time - Turner and the chaos that ensues as they try to fix some past mistakes.
Another plot could be that the OC is a muggle - born with an uncanny ability to see through magical illusions. The Weasley twins, known for their love of creating illusions, initially see the OC as a threat to their pranks. But as they get to know the OC better, they realize that they can use this ability to create even more elaborate and undetected pranks. This would involve a lot of character development for all of them as they learn to trust and rely on each other.
One great 'Weasley Twins x Harry Potter' fanfiction is 'Pranks and Prophecies'. It shows the twins including Harry in their wild pranks while also delving into the deeper magical mysteries at Hogwarts. The story has a great balance between humor and adventure, which is typical of fanfictions involving the Weasley twins.