Well, I think Orion is a really cool shapeshifter character in some fanfics. He can shapeshift into a powerful dragon, which is just amazing. He uses this form to protect Hogwarts from various threats. There's also a character named Nova. She's a shapeshifter who has the ability to blend into her surroundings by taking on the appearance of the environment. It's a very unique power that she uses in really clever ways. And let's not forget about Thalia, who can shapeshift into different mythical creatures and often uses her powers to help her friends in their adventures.
One of the most interesting shapeshifter characters is Ember. In the fanfics, she discovers she can shapeshift at a very young age. She can transform into a phoenix, which is not only a powerful form but also has a lot of symbolic meaning in the Harry Potter universe. Her journey of learning to control this ability and dealing with the expectations that come with it makes her a very engaging character. Another interesting character is Leo. He is a shapeshifter who can take on the forms of different Hogwarts professors. This ability leads to some really funny and also some very tense situations in the fanfic. There's also a character called Luna in some fanfics. She can shapeshift into a mermaid and her underwater adventures as a mermaid add a whole new dimension to the story.
Luna Lovegood often becomes an extremely interesting character in these fanfics. Her unique view of the magical world can lead to some really cool midnight escapades. For instance, she might lead Harry on a midnight search for a rare star - related magical object that is only visible at midnight.
Well, there's this fanfic called 'Shapeshifter in the Shadows'. In this story, the shapeshifter character is sort of an enigma at Hogwarts. They use their power to solve mysteries around the castle. Then there's the fanfic where the shapeshifter is actually a descendant of an ancient magical being and has to learn to control their powers in the modern wizarding world of Harry Potter. I can't remember the exact name though. Also, 'Shapeshifting Bonds' is a fanfic that focuses on the relationships a shapeshifter forms because of their unique ability.
A long - lost relative of Sirius Black could be a shapeshifter. Since the Blacks had many secrets and were involved in a lot of dark magic in their family history, it would be believable for a hidden relative to have this unique ability.
The Weasley twins, Fred and George, are very common. They are the original pranksters in the Harry Potter series, so it's natural for them to be central in many fanfics. Harry Potter himself also often appears in these fanfics, either as a victim or sometimes as an accomplice to the pranks. And of course, Ron Weasley, being their friend, is also frequently included.
Toothless is definitely one of the most popular. Since he's Hiccup's closest dragon companion in the original story, in fanfics where Hiccup is a shapeshifter, Toothless can have a whole new dynamic with him. He might be the one to help Hiccup understand his new abilities, or be protective of him when others are suspicious. Astrid is also popular. She could be the one who discovers Hiccup's secret and has to decide whether to keep it or tell the others. Her relationship with Hiccup, which is already complex in the original, can take on new twists and turns in these fanfics.
Often, Harry Potter himself can be a main character in such fanfics. Imagine him with the ability to shapeshift, which could give a new twist to his battles against Voldemort. He could transform into a snake to spy on the Death Eaters, for instance.
Well, Dumbledore could be a very engaging character in 'Back again' fanfics. He has so much knowledge and power, and if he were to go back, he could potentially prevent a lot of the tragedies that occurred. Neville Longbottom is also a great choice. He could use his new - found courage and knowledge from the future to be a real hero earlier on. And Ginny Weasley, she could change her own story and her relationship with Harry in interesting ways if she goes back in time.
Harry Potter himself is often a central and very popular character. He's usually the one on the journey to become a master enchanter. Hermione Granger is also popular as she often aids Harry with her extensive knowledge. And sometimes, Severus Snape can be a key character, perhaps as a mentor or an obstacle in Harry's path to enchanter mastery.
One interesting concept could be a shapeshifter who uses their ability to infiltrate the Death Eaters. They could change their appearance to gather intelligence and help the Order of the Phoenix.
There might be a fanfic where a shapeshifter character tries to blend in at Hogwarts while hiding their true form. They could shift into different animals to avoid detection and get involved in various escapades around the school, like sneaking into the Forbidden Forest to find hidden magical artifacts.