The famous evil dragoness from Sleeping Beauty!

Tweaked her background a bit so that she's permanently a dragon: Maleficent survives the final battle in Sleeping Beauty, but Prince Phillip's sword takes away her ability to use magic, thus preventing her from changing back to her original human form. In the years after receiving her "curse", she spent her days scouring the land, wreaking havoc across villages out of anger and blind vengeance. But nowadays she's somewhat mellowed out and she behaves much like the dragon she is, burning things, gorging herself, and flying aimlessly wherever she fancies.

Art by dahurgthedragon on e621