Definitely Ginny. Since she's Harry's love interest in the original series, in the fanfiction about them growing up, she has a big role. She could be shown as a strong, independent witch who is equal to Harry in many ways. Draco Malfoy is also a character that features a lot. Sometimes, fanfiction explores his redemption arc further as he and Harry have to interact in the post - war wizarding world.
Hermione could be another main character. Maybe she discovers what's happening to Harry and the author and tries to find a way to reverse it or at least understand it better. She could use her vast knowledge of magic to research the phenomenon.
Fred and George Weasley are also favorites. Their mischievous nature can be amplified in fanfictions. They could create new and even more spectacular magical pranks specifically aimed at Umbridge, like turning her office into a never - ending maze of trick stairs and hidden rooms filled with various magical creatures that drive her crazy.
Hermione is always popular. In these fanfictions, she might play an even more important role in helping Harry adjust to being a girl. Ron could also be a significant character as his reactions to Harry's transformation can add humor and depth to the story. Also, Luna Lovegood might be interesting as she could have some unique insights or interactions with Harry in her new form.
There could be the caretaker of the orphanage. This person might be a strict or kind figure who has a significant influence on Harry's early life. They could be either a source of support or a constant obstacle for Harry.
A forest nymph could be important. She might guide Harry through the forest, teaching him about the plants and their magical properties.
Hermione could be a main character. She would be the one trying to figure out the magical theory behind Harry's cocoon - building and wing - growing. She might be researching in the library, looking for any mentions of similar phenomena in ancient magical texts.
Hermione could still be a common character. Even in fanfiction where Harry is alone, Hermione might be mentioned in his thoughts or in flashbacks as someone who has influenced him. For example, he might recall her advice on how to study magic when he is facing a difficult spell alone.
Hermione could be a main character. As a very intelligent witch, she might assist Harry in his teaching, like helping him prepare complex lessons or providing additional knowledge to the students. For example, when Harry is teaching about ancient spells, Hermione could offer insights from the books she has read.
Hermione could be one. She could come to Degrassi to help Harry. She'd be really good at handling the academic side of things there, like helping students with their studies. And also, she could use her magic knowledge to figure out any magical mysteries.
The Weasley twins could be part of it too. Suppose Harry yells in excitement or anger about a new prank idea that the twins have come up with that might be a bit too dangerous. They could either encourage his yelling or try to tone it down, depending on their mood. And Malfoy might overhear Harry's yell and use it as an opportunity to taunt him, adding more conflict to the fanfiction.