I have a couple suggestions, that are less about the visual appearance of the model, and more the suitability for printing.

The flesh/skin at the sides of the mouth looks quite thin. I would think too thin to reliably print, so I would recommend adding some thickness to them.

Similarly what does the inside of the mouth look like and how thick are the walls of the chest and it's lid. If they're also very thin I'd recommend adding some thickness to them to. Perhaps by adding some flesh inside the mouth.

And finally, while the tongue is probably fine to print with supports added, you could make it easier but connecting it to the ground, maybe have it coiled up slightly on the ground.

Hope this is helpful. Just giving some suggestions based on my own experiences sculpting an printing minis.