Morgalla - half human, half demon. She can appear in her natural half-and-half state, or she can make herself look fully human.
And she has a friend who's a Valkyrie, too!
Check out her story in the Library, in the Sixth Miscellaneous section.
And here is the web site
Here's where you can get the book Diary of a Lonely Demon
If you don't have a Username and Password for the Galleries, get one here