It's possible that in the Pokemon fanfic, Meowth is punished by being forced to do tasks it hates. Since Meowth is usually quite mischievous and often up to no good, the author of the fanfic might make it clean up a dirty and stinky place, like a Pokemon waste disposal area. It would be a very demeaning punishment for Meowth, and it would have to endure the smell and the hard work, all while being supervised by other Pokemon who might mock it.
In a fanfic, Meowth's evolution might be a result of a magical spell gone wrong. Instead of evolving into a normal form, it becomes a hybrid of different Pokemon types. This new form gives it strange and wonderful abilities, like being able to turn invisible or create illusions. But it also has to deal with the confusion of its new identity and how other Pokemon and humans react to it.
One reason could be its loyalty to Team Rocket. In many Pokemon stories, Team Rocket is the bad guy group. So, if Meowth is part of Team Rocket in the fanfic, when they do something really bad like trying to steal a rare and beloved Pokemon from a village, the villagers might catch Meowth and punish it instead of the whole team. They could make it do hard labor, like carrying heavy sacks of Pokemon food around the village all day long. This is because Meowth is more accessible and less intimidating compared to the other members of Team Rocket.
Meowth joining Ash in a fanfiction could also lead to some interesting character development for both. Ash might learn more about the Pokémon world from Meowth's perspective, especially the seedy side that Meowth has been a part of with Team Rocket. And Meowth could learn about friendship and loyalty in a new way, different from what he's experienced with Jessie and James.
Well, it could be about a Meowth that discovers a special power that allows it to mega - evolve not once but twice. Maybe it goes on a journey to find a way to control this new - found power. Along the way, it meets other Pokemon and trainers who either help or hinder its progress.
In this fanfic, the plot could be that Meowth has a change of heart after an encounter with a powerful and kind Pokémon that Ash helps. This makes Meowth realize that Ash's way of treating Pokémon is better. So, he joins Ash. He could then use his unique skills, like his ability to talk, to help Ash in battles and communicate with other Pokémon more effectively.
Well, perhaps it's a story that focuses on the friendship between Meowth and Bonnie. They might help each other out in their respective dreams. For example, Bonnie might be trying to become a better Pokemon trainer with Meowth's street - smart knowledge of the Pokemon world.
One reason could be unrequited love. In the Pokemon world, Meowth has a soft spot for certain Pokemon, like the Skitty. If in a fanfiction, Skitty rejected Meowth's advances, it would make him sad. Another could be his longing for acceptance. Meowth is a part of Team Rocket, but often they don't fully appreciate his skills. He might feel sad and underappreciated in a fanfiction scenario. Also, memories of his past life on the streets, before joining Team Rocket, might haunt him and bring about sadness.
If Meowth joins Ash in fanfiction, it could lead to some really interesting character dynamics. Meowth has been part of Team Rocket for a long time, so there would be a lot of room for him to change and grow. He could teach Ash some of the sneaky tricks he learned from Team Rocket, but in a more positive way. Maybe they'd form a new team and compete in different Pokémon competitions.
Well, one possibility could be that Meowth betrays Team Rocket. Maybe he gets tired of their constant failures and decides to side with Ash and his friends. He might see that they have a more positive and successful approach to their Pokemon journey.
In a fanfic about Meowth evolving, it could be that a powerful enemy forces Meowth to adapt and evolve in order to protect its friends. This evolution might give it new abilities and a different appearance, perhaps more intimidating to foes.