One certainly sees plenty of old pewter chocolate/candy molds around, but much rarer to find an early cast iron one, and even rarer to find skeletons, here three in a row! Indeed, I can find no other iron skeleton mold out there anywhere. The detail on both sides of this mold are pretty great, articulating the skulls, rib cages, and pelvic bones of what I believe are seated skeletons (really they look almost like they are riding bikes!) I think this would have been used for making clear candy rather than chocolate, and if someone should decide use this for making some skeleton lollipops, I sure would love one! 

Each side measures 4 1/2" w x 2 3/8" t x 5/8" d.  Both sides are marked on the outside with what looks to be the number 109. Very good antique condition. Late 19th c. I believe.