Very nice concept Chip, I don't think I ever have seen anything like it and would hope to god I will never get to see one in real life otherwise I'll shit myself. I love the pastel strokes and grainy effects.
Now I'll try my best to point things that I think could improve on this, now take it as a grain a salt cause I haven't critiqued a piece in a long time, so I apologize in advance if anything does make sense what I'm saying, also I'm a terrible writer, and refused to pay for a Grammarly subscription.
The first thing that I would suggest and its something I learned over the years it's to choose one main key light to show your scene usually one that will give you a clear read on your subject and gives the appropriate mood to your scene. In this case, I would say it will be the flames in the back, which will give it a nice dramatic rim light and strong shadows to obscure its faces. I probably dim down a couple of values on the light around the eyes. Also, the top of the eyebrows and hair won't receive any light due to the brown blocking it same goes around the cheeks. The mouth its receiving a lot of light from the front but I don't see any other form being affected by it. I find it helpful to add some cross contours at the earlier stages to help you figure out where the light hits and can't reach.
I also see the light on the ground having a warm temperate to it when the light hitting that forms its that cool tail light, so you can shift that towards the cool side it might fix that. Also since that light, its quite close and that strong you probably want to use a more hard edge to it, at the moment it's far too soft try to connect the shadows it gives a strong read ( something I learn from James Gurney color and light Book). I notice that the rim light in some places has a dark outline around it, and some don't. Try to be keep everything consistent. I would suggest that maybe darken up the area behind the flames and the doggo to pop it up a bit more, it will make the light seem brighter fo shizzle!
Another thing you could start thinking about it's varying up the shapes and spaces in the piece. Like for example the saliva they all seem to be at the length and space apart. It is something that I still struggle with.
Now In the previous attempts, I notice there were trees around that the image that made the doggo look quite massive. I can't tell how big its this doggo on the recent one. Maybe add something to help gauge its size may be something that the creature its hunting or play up with some atmospheric perspective or some clouds going thru it. Make sure its something the audience its familiar with its average size if you decide to do that.
I hope this has been helpful and not so confusing, I'll try my best to answer any questions on my critique. Wish you best on this, it's one my favorite pieces that you have made by far and I can tell you put in a lot of work went into this. Cheers! 
Or at least make an illustration to go with your horror theme 
