Ariel's character also broughta lot of dilemma for Disney artists because they needed to decided whether she was going to be exotic or cute. Amazingly, Ariel's first appearance ended up being very much as that of Alice from "Alice in Wonderland" and she wasn't a red head at first!
Another tiny detail that Disney artists were careful to put together was her hair, it had to have a life of its own! Every hair movement was carefully studed by the artist and it had to look real. Disney built a small tank so that the live-action body model, Sherri Stoner, could swim in it. It is also believed that Ariel's personality was based on then teen-idol Alyssa Milano.
As for Ursula, she also experienced a lot of different transformations. She began as an evil mermaid, then her tail evolved to be an eel's tail. At the end, they decided that her tentacles would give her that special touch that represented her personality.
Some of the other characters were also based on the artists who shared their voices with their characters such as the late Buddy Hackett with Scuttle.