Obviously, Harry himself. His friends Ron and Hermione would surely be in the story. They'd be the first to notice and react to his growth spurt. Hagrid might also be involved, perhaps giving Harry some advice on how to deal with his sudden growth, like how he dealt with his own large size when he was young.
The Weasley family would likely play a role. Molly Weasley would probably fuss over Harry, making sure he has enough to eat to support his growth. And the other Weasley siblings might be a bit envious or just find it really cool. Ginny, in particular, might see Harry in a new light with his growth, adding an interesting dynamic to their relationship.
Well, it could be about Harry suddenly growing taller and stronger. Maybe he starts to outgrow his old clothes and has to quickly get new ones. His new height might also give him an advantage in Quidditch, like reaching the Snitch more easily.
Ruby is often a very popular character in rwby growth spurt fanfiction. Her innocent and determined nature makes her growth, both physical and emotional, very interesting to explore. Yang is also popular. Her strong - willed personality combined with potential changes during a growth spurt can lead to some exciting storylines. Blake is another one. Her mysterious past and the possible ways her growth spurt could interact with her Faunus identity make her a favorite in these types of fanfictions.
Obviously, Harry himself is the central character. Then, there could be characters like Dumbledore who might play a role in guiding Harry about his new heritage. Hermione would also likely be involved, using her knowledge to help Harry understand the Pendragon history.
Dumbledore could also play a role. He might see Harry's weight loss journey as part of his overall growth and offer some cryptic yet inspiring words. Maybe he arranges for Harry to have special training sessions with the ghosts of Hogwarts, who have unique ways of making exercise fun. And of course, the Hogwarts professors like Madam Pomfrey could be involved, ensuring Harry's health during his weight loss process.
Obviously, Harry Potter himself is the central character. Hermione Granger and Ron Weasley are also very likely to be involved. They might try to help Harry regain his hope. Dumbledore, even if he's dead in the original story, could appear in flashbacks or as a guiding spirit, trying to inspire Harry. Snape could also be part of it, as his complex relationship with Harry could add more depth to the story of Harry losing hope.
Neville could be involved too. He has grown into a strong wizard and would surely want to help his friend. Ginny, who has a special connection with Harry, would be at his side constantly. There could also be some new characters introduced, like a healer from a far - away land who has unique knowledge about Harry's condition.
Obviously, Harry Potter himself is the central character as the one being abused and neglected. The Dursleys are also key characters as they are the ones who abuse and neglect him in the original story. Hermione and Ron might also be involved as they could be the ones to discover Harry's situation and try to help him. Dumbledore could also be a part of it, perhaps as someone who failed to notice or prevent Harry's abuse initially.
The main ones are Harry and Ginny. But Fleur and Bill could be involved as well, sharing their own wedding experiences with the couple. Ginny's brothers other than Ron, like Percy, would be there in their formal robes. Percy might even give a speech at the wedding. Cho Chang could be an unexpected guest, showing that there are no hard feelings between her and Harry. And then there are all the Hogwarts professors, like McGonagall, who would be there to bless the union and make sure everything runs smoothly in the magical aspects of the wedding.
In this fanfiction, Luna Lovegood could be an interesting addition. She might have some unique insights into Harry's metamorphmagus ability since she often has a different perspective on magic. The Weasley family as a whole could also be involved. Mrs. Weasley might be worried about Harry's new ability and try to mother him, while the twins could see it as an opportunity for some pranks or to develop new magical products. And then there's Hagrid, who would surely be there to offer his big - hearted support.
Obviously, Harry himself would be the main character. His friends like Ron and Hermione are also likely to be involved. They would probably try to support Harry or figure out what's going on with him.