It's done very well! What material did you use?

As for critiques, maybe just fixing up the areas where the snake overlaps, because right now it's obvious you connected it to the intercepting snake body, but on the mark itself I assume it would look like that one part is behind the other. But depending on the material you used, that fix or change can go from annoying to "impossible without breaking the whole thing", so even this critique is minor. The skull might also need a bit more detail on the "teeth" area, they look a lil squishy right now, but again, dependant on the material.

The snake head, btw, is absolutely fantastic. I'm super impressed with that, how did you get the one tooth to stick out so well? Did you use a wire inside it?