Just looking through Skull Cove right now and the ground-sand tile has a skull on the first page toward the bottom and ground-shore tile has a skull on the third page near the wooden plank. Might be others, there's a lot of files to look through.
As far as Gothic Realms, there are skulls on the walls, will take a little work to be able to use them for ground placement. There's also a skeleton on one of the floor tiles, skeletonfloor to be exact!
There's also the crypt wall in the props section of Gothic Realms.
Not sure what other sets have skeletons, but there should be some others.
) and then just copied/pasted over and over until i basically had one piece of paper filled with skulls. i crumpled up a 1/4 piece of blank paper into a mound and taped it together. then i cut out a section of the skull tiles and then taped it all up over the paper mound.
