So... it's the Nowhere King?

I'm researching Celestial stags for the short story about the plum trees. "Celestial stag" seems to be a poor translation, as they are found in underground mines. And there doesn't seem to be much solid history for where this creature came from. It may just belong to a class of undead demons in Chinese folklore. But they're dangerous - they will do anything to escape the mines and get above ground. And bad things will happen if they do.

So, undead beasts named for stags, and trapped in a place they try to escape imprisonment..

It's the freaking Nowhere King!