One underrated character is Felix. He's always by Peter Pan's side, but we don't really know much about his past or his motives. Fanfiction could explore his backstory, like maybe he was a lost boy who had a really tough life before coming to Neverland and that's why he's so loyal to Pan. Another could be the mermaids. They are often just seen as minor characters, but they could have their own complex society and relationships that could be delved into in fanfiction.
The Echo Cave is kind of an 'underrated character' in a way. You could write fanfiction about it as if it has a consciousness of its own. Maybe it has memories of all the people who have passed through it. Another underrated character is the giant from Jack and the Beanstalk. What if he somehow made his way to Neverland? It would be interesting to see how he interacts with the existing characters. Also, the fairies that are not Tinker Bell could be focused on. They might have their own powers and roles in Neverland that haven't been fully explored in the original story, and fanfiction could be a great way to bring those to light.
Definitely Tiger Lily. She has a lot of potential. In fanfiction, you could focus on her relationship with the other tribes in Neverland, or her own adventures away from the main storylines involving Peter Pan and the lost boys. Also, the Blue Fairy could be an interesting character to focus on in a Once upon a Time Neverland fanfiction. She has her own magic and knowledge, and exploring how she might interact with the Neverland characters, or if she has any secrets related to Neverland, could make for great stories. And there are the dwarves from the Enchanted Forest. What if they somehow ended up in Neverland? Their unique personalities and skills could add a new dimension to the fanfiction.
One idea could be exploring the backstories of the lost boys in more detail. Maybe one of them has a hidden connection to a character from the outside world. Another plot could involve a new villain coming to Neverland who has a different kind of magic that challenges Peter Pan. Also, a story about Wendy's granddaughter returning to Neverland to find a lost family heirloom could be interesting.
In some cases, it could be a corrupted lost boy. Maybe one of the lost boys has turned bad due to jealousy or a desire for power. He sees the hurt girl as an easy target to assert his dominance or to gain something from her, like her friendship with Peter Pan. So he becomes the main source of trouble for the girl in the fanfiction.
The old hermit character. He was only in a few scenes but seemed to know a lot. Fanfiction could explore his past and how he came to have his knowledge. There's also the young apprentice who was often overlooked. He might have some hidden powers or a special connection to the treasures that could be delved into.
One underrated character is Baltus Van Tassel. He's Katrina's father and has a big role in the town. Fanfiction could explore his backstory, like how he came to be such an important figure in Sleepy Hollow. Maybe he had some adventures in his youth that are related to the Horseman legend. Another is the schoolmaster before Ichabod Crane. What was his experience in Sleepy Hollow? What did he know about the Horseman that he might have passed on to Ichabod? And then there's the old woman who lives on the outskirts of town. She might seem like a minor character, but she could be a seer or have some connection to the supernatural forces in Sleepy Hollow.
Rock Lee is often overlooked compared to the main characters. A fanfiction could focus on his journey to become an even greater ninja without relying on ninjutsu. Another underrated character is Shino Aburame. His unique bug - related abilities could be explored more deeply in a fanfiction, like how he might use them in different and unexpected ways.
The neighbor who was briefly shown in the movie could be an interesting character to focus on. We didn't really get to know much about him, but fanfiction could explore his story, like how he managed to survive on his own for so long. Maybe he had some unique skills or knowledge that helped him. Another could be the old man who we saw at the beginning. What was his life like before the invasion? Fanfiction could give him a more detailed backstory.
One underrated character is Forager. He has a really unique perspective as an alien among the team. Fanfiction could explore his backstory more deeply, like his life on his home planet before coming to Earth. It could also show how he struggles to fit in not just with the human members of the team but also with the other alien members who may have different cultures.
One underrated character is that old librarian in the academy. He seems to have a lot of knowledge but is often overlooked. Fanfiction could explore his past and how he came to possess such vast knowledge of magic. Another could be the gatekeeper of a certain magical realm. He has a small role in the original but could have a much bigger story about his loyalty and the secrets he guards.
Rock Lee is often overlooked compared to the main characters. In a fanfiction, his story could be expanded. Maybe he discovers a new form of taijutsu that no one has ever seen before. His journey to master this new style could be really interesting, showing his determination and growth.
Artemis is a character that could be explored more in fanfiction. She has a complex backstory and during the Invasion, she could be given more depth. For example, her relationships with other team members could be further developed, especially how she deals with the stress and danger of the invasion while also maintaining her cover if she still has one at that point.