Luna Lovegood could be a character in some fanfictions. Her unique perspective on magic might lead her to discover or interact with a stag animagus in an interesting way. Also, Hermione might be involved as she's always interested in learning about new magical forms and could be helping a stag animagus character understand their abilities.
Harry Potter himself is often a main character. Since he has a connection to stags through his Patronus, it's common for fanfiction to explore his potential as a stag animagus. Another is James Potter, Harry's father, who was an animagus and took the form of a stag.
In some fanfictions, a new character could be introduced as the stag animagus. This character might be an outcast or a hero in the making. They could befriend Harry or be on a quest related to their animagus form, and their story could be intertwined with the existing characters and events in the Harry Potter universe.
One possible fanfiction could be where Baruto, a character from a different universe, somehow ends up in the Harry Potter world. He discovers Harry Potter's stag animagus form and is both amazed and intrigued. They could go on adventures together, with Baruto learning about the magic in the wizarding world and the significance of the stag animagus. The stag could guide Baruto through the Forbidden Forest, showing him the magical creatures that live there.
Yes, there are quite a few. You can try searching on fanfiction websites like Archive of Our Own. There are some great works where Harry is explored as a stag animagus, often with interesting plotlines that involve his new form in various magical situations, like using his stag form to explore the Forbidden Forest in a way he couldn't as a human.
One common theme is the exploration of Harry's new identity. It often involves how he comes to terms with being a stag animagus and what it means for his role in the wizarding world. Another theme could be his relationship with his animagus form, like how he controls it and uses it to his advantage.
One great fanfiction could be 'The Crossover Chronicles'. In it, the concept of animagus from Harry Potter is combined with Naruto's world in an interesting way. The main character, who has the ability to transform into a stag like in Harry Potter, uses this power in the Naruto universe to gain an edge in battles and also to understand the different cultures of both worlds.
Harry Potter himself is often involved. He might be the one to encounter the first signs of inflation, whether it's a magically inflating potion or an enchanted object. His friends, like Ron and Hermione, are also likely to be part of the story, helping him figure out what's going on.
Ron Weasley could also be a key figure. He might be Harry's loyal friend as always, standing by his side during all the changes that Harry is bringing about in the wizarding world as a god. And there could be new characters introduced as well, perhaps other gods or magical beings that interact with Harry in this new fanfiction realm.
In some cases, Albus Dumbledore could play an important role. His wisdom and power in the wizarding world would make him a key figure in any situation where the two different universes collide. He might be the one to first discover Alexstrasza's presence and figure out how to make use of her abilities in the fight against the dark forces in the Harry Potter world.
Obviously, Harry Potter himself is always a main character. He is the one most directly associated with the concept of death in the original series, what with his parents' death and his multiple near - death experiences.
Ron Weasley could be another main character. He might be initially skeptical about the piano's magic but then be amazed when he sees the extraordinary things it can do. Maybe he accidentally discovers a new function of the piano while fooling around with it in the Gryffindor common room.
Harry Potter himself could be one of the main characters in such fanfiction. Maybe he gets an automail limb after a particularly dangerous encounter with Voldemort. Hermione might also be involved, using her vast knowledge to help understand and improve the automail technology within the wizarding context.