The Ymid walks through the Gate
This is a rendering of a creature from the mind of James Garrison, and more detail can be found  here:

http://hereticwerks.blogspot.com/p/free-pdfs.html

Look for his adventure called Clatterdelve.

The Ymid is coming through a gate that leads to the vale of Pnath, a location described in the Dreamquest of Unknown Kadath.