Not sure if you're entering this piece for the competition, but I'll crtique it as though you were.Because the artwork would be printed in small deminsions, one only really sees charizard's head, wing shape and moon. It's too dark. Instead of black, perhaps use darker, blue-ish hues for the background elements. It'll help make the orange pop out. The contest asks to see pokemon living its daily life routine. Because the charizard is asleep, the narrative becomes more about the resourceful basic pokemon. This is a problem if the aim is to create an artwork for a charizard card. If charizard were awake, it's more about it being generous towards others. Maybe the wing can be lifted up to act as a canopy? While the contest rules didn't ban adding additional figures in the competition, it wasn't supportive of the idea. However, the winning piece from the last competition had both a pokemon and trainer in a piece. Would you be interested in swapping out the wild pokemon for a trainer? I would reexamine the (gol)bats + moon in the background. The moon takes one eyes away from the scene.
Hope these suggestions are of help. Good luck with the contest.