A white tiger as a familiar in Harry Potter fanfiction could work in various ways. It could be from a different magical realm and somehow end up in the wizarding world. It would bring with it a new set of magical skills and instincts. For example, it might be able to sense dark magic from a greater distance than normal familiars. And when it comes to the Hogwarts environment, it could form an interesting dynamic with the school's mascots, like the Gryffindor lion, creating a contrast between wild and domesticated magic.
A nekomata could fit in as a rare and powerful familiar. It could be from a far - off magical land and brought to Hogwarts by accident or on purpose. For example, it might have been smuggled in by a dark wizard initially but then escapes and finds Harry.
Perhaps the tiger is a result of a magical experiment gone wrong. Some wizard was trying to create a new kind of familiar and ended up with a tiger. And then, through some twist of fate, the tiger becomes Harry's familiar. Another possibility is that the tiger was a spirit animal that was drawn to Harry because of his unique magical aura.
Well, in this fanfiction, the tiger familiar may have special abilities. It could be able to sense danger before Harry does. So it would lead Harry away from places where there are traps or lurking enemies. Also, being a large and intimidating animal, it can act as a deterrent to some of the less brave adversaries that Harry might face, making it easier for him to get through certain areas or tasks.
If a character in Harry Potter fanfiction had a white tiger as a familiar, it could change a lot of things. For starters, it would be a huge advantage in battles. A white tiger is large and fierce, and could intimidate opponents. In terms of magic, it might have some special abilities related to nature magic, since tigers are part of the natural world. Also, the bond between the character and the white tiger would be very deep, and it could be a source of emotional support as well as magical power.
A sucubus familiar could be a magical being from a far - off and dark corner of the wizarding world. It could be that a powerful and unorthodox wizard has managed to bind it as a familiar. In the Harry Potter universe, it might be seen as a very dangerous and controversial choice. For example, Dumbledore might be extremely cautious about it, while some dark wizards might be envious and try to steal it.
A Quetzalcoatl as a familiar in the 'Harry Potter' fanfiction universe would bring in a whole new cultural aspect. The creature has strong ties to Mesoamerican mythology. It could interact with the magic of Hogwarts in interesting ways. For example, its connection to the sun in its native mythology might translate into some sort of light - based magic within the 'Harry Potter' context. It could also have a special bond with Harry that goes beyond the normal familiar - wizard relationship, perhaps due to its more ancient and powerful nature.
Harry Hook often fits in as an alternate version or a new character added to the existing Harry Potter universe in fanfiction. He can bring new storylines and interactions.
Riku might be a character who has been summoned to the 'Harry Potter' world by a powerful spell gone wrong. Once there, he has to adapt to the rules of magic in this new world. He could start by learning basic spells at Hogwarts and gradually become a key figure in the fight against the dark forces, using his own brand of courage and determination that is different from the typical Hogwarts students.
The Bard can fit as a new kind of magical being. He could bring his own brand of magic, perhaps music - based magic, that is different from what the wizards in Hogwarts are used to. For instance, he might be able to use melodies to heal wounds or break curses.
It could be that Element 115 is related to the dark arts in the fanfiction. Maybe it was once used by dark wizards to create powerful and evil spells, and now it has resurfaced, causing a stir in the wizarding world. It might be up to Harry and his friends to figure out how to deal with it. This would add a new and exciting plotline to the familiar 'Harry Potter' world.