So the Medusa has been done before, but your execution is what sets your version apart from others. The mix of beauty and beast, the swirling composition, and the the color choice all add a lot of appeal to your design. To me, this has an almost art nouveau feel, which I like very much and it's appropriate to the subject matter.
My only gripe is logo placement. On the front, I would've liked to see either the logo a little smaller or moved from upper right to lower right (to act as a base, behind the serpent). On the back, the logo needs to be smaller, or you're going to make everyone's butt look big. ;D
I love what you were able to pull off here and it's giving me a few ideas for a larger project I'm working on where the Medusa gorgon is part of it. The mono-chromatic image here is nice and there's a good sense of composition with the hand leading up to the face and the rest of the image.