What are some interesting plot ideas for Invader Zim OC fanfiction?

One idea could be that the Grimm from RWBY somehow end up in the Invader Zim universe. Zim, thinking they are some new form of alien threat, tries to study them while Dib sees them as a chance to prove himself by fighting them. Meanwhile, the RWBY characters are on a quest to get back to their own universe.

An interesting Invader Zim fanfiction could center around an alternate universe where Zim is actually a good guy sent to protect Earth from other threats. Or it could be about Zim and Dib getting stuck in a time loop and having to figure out how to break it. You might also consider a story that focuses on the strange and unique creatures in the Invader Zim universe and how they interact with Zim and Dib.

One plot idea could be that Zim discovers the power of the Sailor Scouts and tries to use it for his own evil plans. Maybe he thinks he can use their magic to finally take over Earth in a more powerful way.

One idea could be a crossover where Zim tries to take over Townsville and the Powerpuff Girls have to stop him. They initially underestimate Zim because of his small stature but soon realize his advanced alien technology is a real threat.

Here's a more detailed fanfiction idea. In a world where the Powerpuff Girls have been unable to stop a powerful new villain, they seek help from Dib, who then brings them to face Zim. Zim, thinking he can use this situation to his advantage, offers to help them. But in reality, he has his own plans to take over both Townsville and the Earth. As they work together, the Powerpuff Girls start to notice Zim's true intentions. Bubbles tries to befriend Gir to get more information, while Blossom tries to keep Zim in check. Buttercup is more skeptical and constantly on guard. Meanwhile, Dib is trying to document everything for his own records, hoping to finally prove Zim is an alien once and for all.

One idea could be a crossover with 'The Simpsons'. Zim could try to infiltrate Springfield, thinking it's a key Earth location for his invasion plans. Maybe he mistakes Homer for a powerful Earth leader and tries all sorts of wacky schemes to take over the town through him.

One idea could be Zim getting sucked into a black hole and having to find his way out in a strange new dimension filled with bizarre creatures. He could use his usual over - confidence and wacky inventions to try and navigate this new world.

One interesting concept could be the exploration of Zim's character in a darker light. Maybe he's more menacing and his plans are even more devious. For example, his attempts to take over Earth could involve more cruel and calculated actions towards the humans.

One common theme is the struggle for acceptance. OCs often face challenges in being accepted by the existing characters in the 'Invader Zim' universe, whether it's by the Irkens or the humans.

One interesting Invader Zim fanfic could be 'The Green Menace Returns'. It continues the story with Zim coming up with even more outlandish plans to take over Earth. Another good one is 'Dib's Discovery', which delves deeper into Dib's investigations of Zim's true identity. And 'Gir's Adventures' is also fun as it focuses on Gir's wacky antics around the city.