A really interesting plot could be where the OC is turned into a cat. In this form, they discover a secret underground cat society in the city. This society has its own rules, hierarchy, and even a cat - only language. The OC, as a cat, has to earn the respect of the other cats while also trying to figure out how to break the spell. They might get involved in cat - related adventures like stealing fish from a mean old fisherman or rescuing a kitten from a dog.
One idea could be that the OC, turned into a small animal like a mouse, has to navigate a huge mansion full of traps set by an evil wizard who cursed them. Another could be that as a bird, the OC tries to find a way to reverse the transformation by seeking a magical flower on a remote island.
The OC turned into a fox might find themselves in a forest where they have to team up with other forest animals to protect their territory from hunters. This could involve a lot of strategy and communication, despite the language barriers among different species. They could learn about the unique abilities of each animal and use them to their advantage. For example, the squirrels can hide things in high places, the deer can sense danger from afar, and together they create a defense system.
One idea could be that Dean turns into a wolf. He could use his new wolf instincts to hunt monsters more effectively, but also struggle with the wild side of his new form. Sam might become an owl, using his enhanced vision to spot clues from high above. Castiel could be turned into a deer, which would be ironic considering his angelic nature. He'd have to learn to be more in tune with nature.
Well, perhaps the oc is cursed by an evil witch to be turned into a kitten as a form of punishment. In this case, the oc has to go on a quest to find a rare magical flower that can break the curse. Or, the oc could be part of a scientific experiment that goes haywire and turns them into a kitten. They then have to escape the laboratory and find someone who can understand their situation and help them change back. Also, it could be that a jealous rival uses a powerful talisman to transform the oc into a kitten, and the oc must outwit the rival to regain their human form.
Perhaps an OC is a young archaeology student who idolizes Nathan Drake. They manage to get involved in one of his expeditions through sheer determination. Along the way, they learn from Drake and also teach him new things about modern archaeological research methods. It could be a story of growth and adventure for both characters.
In 'FNAF Turned Human Fanfiction', a great plot idea could be the human - turned - animatronics trying to find a way back to their original forms. They could face challenges like discrimination from humans who remember them as terrifying animatronics. Also, their new physical forms might have some special abilities or weaknesses that add to the story.
One idea could be that Superboy is hit by a strange alien device that changes his gender. He then has to deal with the new physical limitations and social expectations while still trying to be a hero. For example, he might struggle with the different way people treat him as a girl and how to use his powers in a more feminine body.
One idea could be a scientist who is experimenting on artificial intelligence and accidentally gets his own consciousness transferred into a robotic body. He then has to deal with the new limitations and capabilities of the robotic form while trying to find a way to reverse the process.
One plot idea could be that Link, as a girl, has to hide her true identity in a world that doesn't expect a female hero. She could face challenges like being underestimated at first but then prove herself in battles. Another could be that she forms unique relationships with the other characters, like a different kind of friendship with Zelda. Maybe she also has to deal with newfound emotions and how they affect her heroic duties.
Maybe in this fanfiction, Naruto as a female could develop a different kind of relationship with Sasuke. Since the dynamic between male - female friends can be distinct from male - male friendships, it could lead to new story arcs and character growth for both of them.
One idea could be a modern-day high school student who gets turned into a vampire and has to hide it from their friends and family while dealing with the newfound powers and bloodlust. Another could be a historical setting where a vampire turns a noble during a time of war and they must navigate the political and social implications. Or perhaps a story about a vampire who turns a detective, and together they solve supernatural crimes.
One idea could be an OC who is a lightning - style user in Kumogakure and has to face a powerful enemy from another village. The OC could discover a new jutsu during the battle.