Elizabeth Bathory, and I have no idea. I found it in a Google Image search. I tried reverse image searching it and just got links to a bunch of places it had been shared or one person that had it as their avatar on twitter.
Yeah, I thought either you drew it or it was from dA. I assume the artist gave you permission to use it? (Not to sound rude or anything like that, just some artists don't like their stuff being used around the web.)