Major adoration for this. Very realistic and incredibly spooky. Only minor nitpicks are that the slits in between the ribs would show small glimpses of the side of the ribs and organs in the thoracic cavity or muscular chest wall surrounding the ribs, however if you are trying to portray an empty rib cage there would be tiny glimpses of light through the torso. Additionally, adding a little shading around the teeth to show where the teeth rest adds some realism. Again these are incredibly nitpicky details and I really love the picture as it is, however, I thought it might be a bit constructive since you're asking for critique. I mean absolutely no offense by the comments I added here and I'm definitely going to be looking for more rotting awesomeness :)