In my active blog, Just A Tad, I talked about finding some treasures when I was cleaning my studio. The one I didn't scan was this little sketch Mike Mignola did while we talked about a giant bat god stalking the ruins of a Mayan Temple. It turned into a great sequence in Sword of Storms.
Anyway, here's the scan, and if you haven't visited already, check out my other blog which mostly talks about animation but there's other stuff too.