Dumbledore, if he were still alive in the fanfiction, would likely have some wise words and advice for Harry. He might have some secret knowledge about dragon transformations that could be crucial in helping Harry. Also, Neville could come in handy as he has proven to be brave and resourceful, and he might be able to find some rare plants that could be of use to Harry in his new form.
Hermione would surely be one of the first to help. She is highly knowledgeable in magic and would likely try to use a healing spell or find a potion to stop the bleeding.
Hermione would most likely help. She's always been there for Harry, and with her vast knowledge from books, she could offer a great deal of advice on how to take care of the dragon egg. Ron might also be involved. Despite his initial fear of things, he has a brave heart and would probably stand by Harry's side.
Ron and Hermione are the most likely ones. They are his best friends and have always been by his side through thick and thin. They would probably follow him without hesitation and use their own skills, like Hermione's vast knowledge and Ron's loyalty and practical skills, to assist in the ship - stealing adventure.
There could be some new characters introduced in the fanfic. Maybe a powerful wizard from a far - off land who has heard of Harry's plight and decides to help. Or perhaps a group of outcasts in the wizarding world who see Harry as a symbol of their own struggle against the unjust system and come to his aid.
Dumbledore might offer some guidance. He has vast knowledge and experience. He could tell Harry about the significance of different elements in a staff and how to combine them to make a truly powerful and unique magical tool.
Dumbledore might help in a spiritual or advisory way. Even though he's passed away, his wisdom could be passed on through memories or some magical means. Also, Hagrid could be a great help. He could assist in building areas suitable for magical creatures with his love and understanding of them.
His best friends Hermione and Ron would surely be there to help. Hermione with her vast knowledge of magic could research about the egg, and Ron with his loyalty would stand by Harry's side in any danger related to the egg.
It's possible that an old acquaintance from Hogwarts who has family ties in America could assist him. This person might already have a network in America and could introduce Harry to important people. Also, there could be some reclusive magical scholars in America who, out of curiosity about Harry's powers and his role in the UK, decide to help him. They could teach him new magical skills that are specific to the American wizarding world.
Ron might be there too. He could use his skills in handling magical creatures to populate the island with friendly ones. And he could also help with fishing in the surrounding waters using magic, providing food for those on the island.
His friends from Hogwarts, like Ron and Hermione, are likely to help. Ron could bring his family's practical knowledge of wizarding homes and Hermione would contribute with her extensive research skills.