I don't like it. I think the composition lacks a focal point. It's like "design diarrhea." you just put a bunch of stuff onto a canvas and gave no thought to how the viewer's eye will move through the piece. It needs a starting point; which could be dictated by rescaling a lot of your subjects. Everything is kinda all the same size/scale. The mouth should be HUGE, billowing puffs of pudrid smoke. The smoke itself should blend in with the clouds up top-maybe mush it into them with the smudge tool? dunno. But right now it's "smoke image over clound image" not "smoke turning into clouds/thus havinga a negative effect on our well being." Also, i think the smoke should only come from the mouth, having it emit from 2 places makes my eye bounce between the two objects-so still again, no focal point.
good luck!