Sister?

Eris???

They both are greek gods in a way :)

Maybe Eris? Madame Medusa has similar hair...Belle could be her sister even though she doesn't look all that much like her - I think they work as sisters - Kim Possible, Jessica Rabbit, o how about Giselle o anastasia (I know she's not disney but still...)

Vanessa's the only person I could think of. Sorry.

o how about Belle ... o Jane? I think they look a wee bit similar. Maybe tu could just change some of their features.

Um, maybe tu could use Giselle o Thumbelina? Vanessa is the the only evil person I can think of that's similar to Ariel.

A villain that could be Ariel's older sister is Eris from barbie A Mermaid Tale. She has red-orange hair and is a mermaid, she also has legs at the end of segundo movie. Her features aren't that similar but she might work. A lot of those listed are those I would have suggested too.

A villain that could be Ariel's older sister is Vicky. Vicky is an evil babysitter. I have a picture of Vicky in my photos.