Jim Zubkavich worked on the ill fated Legends of Zork game and created some wonderful art for the game. Zork was text based and the thing about Zork that I found most difficult to picture was the dangerous and frightening Grue. It should be nightmare incarnate.
So how do you bring this creature to live without spoiling what your imagination can do better? I think Jim Zubkavich did a fine job with his grinning monster in the darkness.