Stone or Wood?

Stories have been told for years about changelings ossifying when they die.
So, how does that work? What is really happening?
Well, those humans who are capable can initially become changelings by performing ritualised animal acts.
When they are fully developed changelings, they can manifest different parts of different animals at the same time, like a kind of ‘cut-up’ mutation. This is called a “Burrough’s” state, and cannot usually be maintained for very long.
Once changelings become accomplished enough, they can leave their bodies behind entirely, and, as they do, they leave behind a wooden or stone form.
Other changelings can still communicate with the disembodied changeling through this stone or dead-wood form.