The concept for Nucklavee changed very late in the process. So late, in fact, that Trevor Hairsine had already provided one sketch. And Brady Dommermuth and Doug Beyer needed to convey the new idea quickly and efficiently. The simple solution was to have concept illustrator Richard Whitters dash off a sketch to show Trevor what Doug and Brady were thinking.
Of course, that just moved the difficulty to a different level; how could Richard know what Brady and Doug were thinking? Naturally, the solution was for Brady and Doug to draw sketches for Richard to use as a guide for his sketch for Trevor to do a new sketch.
All that is a long way of explaining this mysterious paper that showed up on the Art Wall one day last year:
And, skipping a few sketches, here's the final version: