Maybe there's a misfit ghoul in Ghoul School who feels out of place. She runs away and ends up in Royal Woods near the Loud House. One of the Loud kids, like Luna, finds her and decides to help. Meanwhile, back at the Ghoul School, they think the misfit ghoul has been kidnapped by humans. So some of the ghouls come to find her. The Loud family has to prove they mean no harm and help the misfit ghoul find her place in both worlds.
Well, perhaps the ghouls from Ghoul School are on a field trip to the human world and end up in Royal Woods. They meet the Loud family and chaos ensues at first as the Loud kids are scared. But then they realize the ghouls are friendly. Together, they have to figure out how to get the ghouls back to their school before the sun rises, which is dangerous for the ghouls. And along the way, they learn about each other's cultures and make new friends.
A plot might involve a ghoul ending up in the Loud House world. This ghoul could be on the run from other ghouls or the CCG in its own world. In the Loud House, it has to hide its true nature from the Loud family while also trying to adapt. The Loud kids start to notice strange things happening around the house, like missing food (because the ghoul needs to eat). Eventually, they discover the truth and have to decide whether to help the ghoul or turn it in.
I think Luna from the Loud House would be really interesting. She has that rocker vibe which could mesh well with the spooky and unique nature of the ghouls. And then there's Spectra Vondergeist from Ghoul School. She could use her ghostly abilities to have some cool interactions with the Loud kids. Maybe she could play pranks on them that are more friendly than scary as they get to know each other.
One possible plot could be that Casper, the friendly ghost, gets lost in Royal Woods where The Loud House is located. The Loud kids discover him and at first are scared, but then they realize he's friendly. Together, they help Casper find his way back to the Ghost World while having all sorts of wacky adventures in Royal Woods, like trying to hide Casper from their parents and getting into spooky yet funny situations at school.
A cool plot could be that Mr. Krabs discovers a new market in Royal Woods. So he sends Spongebob and Squidward there to set up a Krusty Krab branch. The Loud kids are excited about the new restaurant, but Squidward is miserable as always. Lincoln and Spongebob team up to make the new Krusty Krab a success, facing challenges like dealing with local competition and getting used to the different customers in Royal Woods.
Well, maybe there's a portal that opens up between Royal Woods and Bikini Bottom. Spongebob and Patrick come through to the Loud House world. Patrick could be really confused by all the human stuff and keep getting into funny situations like trying to eat the furniture thinking it's food. Meanwhile, Spongebob and Lincoln team up to solve a mystery that involves a missing item from both their worlds. It could be something like a special kind of jellyfish that has magical powers and it has ended up in Royal Woods.
Well, it could be that one of the FNAF animatronics gets sent to the Loud House world by accident. Let's say Freddy. Freddy then starts to interact with the family. He might mistake the Loud family for the pizzeria staff. Lincoln and his sisters would have to work together to either fix Freddy and send him back or find a way to co - exist with him. The younger siblings like Lily might be curious about Freddy rather than scared at first, which could add a cute element to the otherwise potentially spooky crossover.
Well, it could be about the Loud family getting sucked into the Kingdom Hearts universe. Maybe Lincoln could be the main character who teams up with Sora. They'd go on adventures across different Disney - inspired worlds within the Kingdom Hearts setting, while also trying to find a way back home. Along the way, they might meet some of the Loud sisters who also got trapped and they all use their unique skills to fight off Heartless.
One idea could be that the Loud sisters get recruited by WOOHP. Maybe Lincoln accidentally discovers a WOOHP gadget and the spies come to retrieve it. They notice the Loud sisters' unique skills and talents. For example, Lori's bossy nature could be useful for leading missions, and Leni's fashion sense could help with disguises. They all team up to stop a villain who is using a new technology to take over the world.
Well, one possible plot could be that the Loud family somehow gets trapped in the Sword Art Online world. Lincoln could be the main character trying to find a way out for his family. He might team up with some of the SAO characters, like Kirito, to fight the bosses and clear the levels. Maybe the sisters would have unique skills within the game based on their real - life personalities.
One possible plot could be that Naruto and his friends are sent to the Tokyo Ghoul universe by some sort of space - time jutsu gone wrong. Naruto, with his strong sense of justice, would be immediately intrigued by the situation of the ghouls. He might try to find a way to co - exist between humans and ghouls, using his ninja way. He could team up with some of the more sympathetic ghouls, like Kaneki, and together they fight against the more extreme elements on both sides, whether it's the violent ghouls who only see humans as food or the humans who want to exterminate all ghouls without question.