Obviously, Lily is one of the main characters. She's the mermaid around which the story revolves.
Another great fanfiction idea could be Lily's encounter with a lost human at sea. Since mermaids are often fascinated by the human world in these stories, Lily might be tempted to help the human get back home. But this would be a difficult task as she has to keep her existence a secret from other humans while also facing the dangers of the open sea.
Most likely, the mermaid is the main character. There could also be a human who stumbles upon the mermaid. Maybe a young boy or girl who is curious about the lake and ends up meeting the mermaid. And perhaps there are other creatures in the lake like a wise old turtle or a friendly water sprite that play important roles in the story.
Prince Eric could be a main character. He would be important as he is Ariel's love interest. Also, King Triton, Ariel's father, could play a significant role as he would be concerned about Ursula's return and want to protect his daughter and the kingdom.
I think Misty from the Pokemon world could be a main character in this fanfiction. Since she has a connection with water - type Pokemon, she could easily fit into the underwater world of The Little Mermaid. Along with her, a Psyduck would be there. Psyduck's clumsy yet powerful abilities could add an interesting element to the story. And of course, Ariel would be a main character. She could learn a lot from Misty about the Pokemon world and they could team up to protect both their worlds from any threats.
Well, Athena herself is of course a main character. She is often depicted as a strong - willed and curious mermaid. There might also be her friends in the underwater world, like other mermaids or sea creatures such as a wise old octopus who gives her advice.
Melody, a mermaid, is one of the main characters. She is probably the central focus, with her own dreams, desires, and challenges. Alex is also a main character. He might be a friend or a love interest to Melody. He could be from a different part of the ocean or have a special connection to the surface world. Together, they form the core of the story in the fanfiction, and their interactions drive the plot forward.
Obviously, Ariel would be one of the main characters. She'd be the mermaid trying to navigate high school life. Eric could also be there as the love interest. Maybe Flounder could be her sidekick, a fish - out - of - water (literally) in the high school, always getting into comical situations. And Ursula could be the school bully or the antagonist who tries to make Ariel's life miserable.
The main characters are often Elsa and Ariel. Elsa has her ice powers which create an interesting contrast with Ariel's life in the sea. They are both strong female characters with different abilities and backgrounds, so it's exciting to see them interact in fanfiction.
Ariel is the central character, a mermaid longing for a different life on land. Prince Eric is the object of her affection. Ursula, the sea witch, is a crucial character as she creates the conflict in the story. Additionally, Ariel's father, King Triton, is also a character in the story. He rules the underwater world and at first opposes Ariel's fascination with the human world. Ariel's friends, like Flounder and Sebastian, add humor and support to the story.
In the Little Mermaid story, Ariel is a central figure. She has a beautiful voice and a longing for the human world. Prince Eric is a charming prince from the human realm. Ursula is a menacing character. She makes a deal with Ariel. King Triton, as Ariel's father, has the power over the underwater domain. Flounder, Ariel's fish friend, and Sebastian, the crab, also play significant roles in the story.