I like your drawing style Nate. It looks cool. Very expressive in line variation, shape of mouth and shape of eyes, arch of eye "brows", angle, everything!
I'm not sure how I feel about his nose. Did you try without it? Does it look too empty that way?
The Beetlejuice resemblance could be changed if his mouth is red or a purple with less blue. Maybe change the colors in his eyes too.
In these still drawings his arms and tail/trail look more like white fire. Which maybe you wanted but I think maybe it doesn't convey his body as well as it could.
Your shading is very good-looking from a technical standpoint but I'm not sure about the shape that it implies, for instance the bright spots on the top right of his face, are they bumps?