Well, perhaps the characters from Harry Potter are magically transported to the realm of Fod where they encounter the fleet. Harry and his friends could form alliances with the Fodians who own the fleet. Together, they face challenges like dealing with strange Fodian magic and creatures, all while trying to find a way back home. Maybe they also discover that the Dark Lord Voldemort has some connection to an evil force in Fod, and they have to defeat both threats.
Definitely Harry Potter himself. His courage and magical abilities would make him a key figure in any adventure involving the fleet of Fod. Hermione would also be great as she could study and figure out the Fodian magic related to the fleet. And Hagrid, because his love for magical creatures might help in dealing with any strange beasts associated with the fleet.
Well, perhaps the 'Fleet of Fog' enters the wizarding world and the wizards initially mistake them for some new kind of dark magic creatures. Harry and his friends then have to figure out what they are and find a way to either make peace or drive them away. The wizards could use their magic to try and understand the technology of the Fleet of Fog, like Ron trying to figure out how their engines work with a simple 'Engorgio' spell on some of the parts to see what happens.
I think Neville could be an interesting main character in this crossover. He has grown so much in the Harry Potter series, and his knowledge of plants could be used in some unique ways against the Fleet of Fog. For example, he could use some magical plants to either hide Hogwarts from the Fleet of Fog's sensors or use them as a form of defense. From the Fleet of Fog, a young and curious engineer could be a main character. They would be fascinated by the magic and would try to figure out how to incorporate it into their technology. Ginny Weasley could also be a main character, with her strong will and magical abilities.
Well, in fanfiction, just about anything can happen. Harry Potter having a fleet is not out of the question. It could be part of a large - scale war scenario where he needs a fleet to transport troops or magical artifacts. Or it could be for a more peaceful exploration purpose, like discovering new magical islands. Writers can really let their imaginations run wild with such concepts in fanfiction.
A fleet of magical ships is also a possibility. These ships could be made of magical wood and have various enchantments. They might be able to travel between different magical dimensions or through dangerous magical waters. Maybe they are crewed by a mix of wizards, magical creatures, and even house - elves, all under Harry Potter's leadership in the fanfiction world.
Adaptation is a major theme. The characters in the fleet of fog have to adapt to the new rules and situations in the crossover. Also, discovery is common. They discover new powers, new species, or new technologies during the crossover. It makes for very interesting storylines as they figure out how to deal with these new things.
Sure, it's quite possible. Fanfiction writers love to blend different fictional worlds. In a 'The Mummy (2017)' and 'Harry Potter' crossover, we could see the mummy's powers being pitted against the spells of Hogwarts students. Maybe the mummy is brought back to life in the wizarding world and causes chaos. There are endless possibilities for interesting storylines in such a crossover fanfiction.
One idea could be that Tinkerbell finds her way into the wizarding world of Harry Potter. Maybe she gets accidentally transported there by some magical mishap. She could use her fairy magic in Hogwarts, like helping to repair broken objects in a more sparkly and unique way compared to the Reparo charm.
A popular one is 'Fem Harry and the World of Middle - earth'. This fanfic is really interesting because it crosses over the Harry Potter universe with Tolkien's Middle - earth. Here, Fem Harry has to adapt to the very different cultures and magic systems in Middle - earth, and there are some great character interactions that add depth to the story.