Melody has a sassy and headstrong personality which reflects upon the personality of her mother in her younger years; but her insecurity around others and socially-awkward tendencies seem to stem more from her father. While Sebastian states that Melody is "just like her mother" in The Little Mermaid II, many similarities exist between Melody and her father, Prince Eric. Her sense of adventure, curiosity, and willingness to take risks exist in both Ariel and Prince Eric; but her mild shyness stems from a sheltered upbringing and her father's personality. Melody's curious nature leads her to collect all sorts of items from the sea, a parallel to her mother at age 16. Melody's swimming proficiency and ability to hold her breath for long periods comes from her mermaid heritage. She is also shy around boys, becoming quite flustered when a mer-boy she found attractive tried befriending her. While she also goes to the sea despite her mother telling her not to, Melody doesn't know why she isn't allowed and is against rules that make no sense or doesn't have a good purpose to follow it.
Melody is a 12-year-old tomboyish princess of average height and build for her age. She has straight/slightly wavy black hair, often tied back with a green hairtie in a ponytail, and blue eyes. Melody seems to have inherited a fairly even blend of traits from her parents. Her hair is the same color as her father's, and she inherited her mother's eyes, smile, nose, and facial structure. It is also possible that Melody inherited Ariel's beautiful singing voice, as the two were heard side by side in "For a Moment", a duet between Melody and her mother. Eric also gave her his skin tone and black hair and eyebrows. For most of the film, Melody is seen barefoot and in her underclothes, which is a separate pair of frilly white calf-length pantalettes and a matching button-front camisole with a green bow; the pantalettes cover the bottom half of her stomach and is seen barefoot while in this outfit. As a baby, she was wearing a pink and white dress and her bow also has the same colors. While in mermaid form, Melody retains her camisole, but her pantalettes and legs are replaced by a pink tail; her navel is also visible. She also has a pink and white ballgown and a yellow casual dress both with short puffy sleeves. Since she found it, she wears her locket that has her name on it.