exposed_bone

When an otherwise/mostly intact person, animal or creature has bones that protrude through the skin or does not have an outer layer covering the bone(s). That outer layer may also be transparent.

This does not include bones that are visible through the skin.

A fully visible skeleton does also not fall under this tag, but should rather be tagged as skeleton.

Exposed bone may or may not mean gore/guro. Many illustrations with this tag achieve the visible bones through magical or imaginary methods. X-ray can also be used to show bones.