I have currently done a art piece of the Little Mermaid called Ariel. She does not look like the original, I have made her my own with more life like features and realistic base.
Do I have the right to sell this? Or is it copyright from Disney?
The fact that you call it "Ariel" and/or "The Little Mermaid" would tend to lend weight to any claim that the infringement was not inadvertent or co-incidental.
Exactly who could sue you depends on who thinks you are infringing their copyright.
That could be either Disney, or the family of Edvard Eriksen (the Dane who sculpted the original).