Perhaps Harry befriends a group of imps that are usually seen as pests. He realizes they are actually very intelligent and they help him in his search for Horcruxes. They use their small size and ability to go unnoticed to gather information for Harry. In the process, he has to defend them from other wizards who want to get rid of them.
One possible plot could be that Harry discovers a misunderstood dark creature, like a werewolf cub that has been separated from its pack. He decides to befriend it and protect it from those who would harm it just because of what it is. As he befriends the cub, he learns about its unique abilities and how it views the wizarding world.
The Acromantula. Harry could come across a young Acromantula that is different from the rest of its kind. Instead of being aggressive, it shows an interest in learning about the human world. Harry, being the kind - hearted person he is, decides to befriend it. He might even teach it some basic spells or communicate with it using Parseltongue.
One common theme is acceptance. Harry often has to convince others in the wizarding world to accept the creatures he befriends, as they are usually seen as outcasts or dangerous. Another theme is the power of friendship. The bonds he forms with the creatures help him in various ways, like solving mysteries or facing enemies.
Maybe the goblin is an outcast in its own community. Harry befriends it, and they discover a conspiracy within the wizarding world and the goblin banks. As they become friends, they use their combined knowledge of magic and goblin lore to expose the conspiracy. Along the way, Harry learns about the complex history and culture of goblins, which changes his perspective on the magical world.
Werewolves are also a popular dark creature in fanfiction. Writers may explore their relationships with other characters in more depth, like how they interact with Hogwarts students. For example, a werewolf character could be a misunderstood outcast trying to find his place.
Dark creatures can be the main source of conflict. For example, if a Dementor plague is introduced in a fanfic, it can drive the characters to find a solution, like a new spell or artifact to repel them. They can also be used to create moral dilemmas. If a character is bitten by a werewolf, how the wizarding community treats that person can be a big part of the plot.
Well, it could start with Harry accidentally stumbling into Lucifer's realm. Lucifer, being curious about this young wizard, decides not to harm him but rather befriend him. They might then form an alliance to fight against a common enemy, like a powerful dark wizard who has made a deal with some other dark forces that Lucifer is also opposed to.
The plot could involve Harry Potter having a special connection with magical creatures that no one else has. He might discover a new type of magical creature and learn its secrets, which could help him in his fight against the dark forces.
One popular 'Harry Befriends Creatures' fanfiction is 'The Creature Keeper'. In this story, Harry discovers a hidden world of magical creatures in the Forbidden Forest and befriends a rare and powerful creature. It's full of exciting adventures and heart - warming moments.
It could be about Harry Potter having some sort of connection or role as the 'king' of dark creatures in a fan - created story. Maybe he discovers a hidden power within himself that gives him control over these usually feared beings.
In Harry Potter fanfiction, the Boggarts can be very interesting. Writers might create unique forms that the Boggarts can take, based on the fears of different characters. The Thestrals are also popular. Fanfics could explore their connection to death in more depth or have them play a more significant role in the wizarding world. Additionally, the Nundu is a dark creature that might be given more detailed descriptions in fanfiction, like its venom having even more deadly effects.