My friend SuperStinkWarrior gives great advise about the well displayed foreshortening of the character in this shot. There haven't been many scenes of a characters going down a chimney from the interior since the Grinch in my opinion. Though it's hard to imagine any character having any sense about going down a chimney while the fire is still lit. If so, then smoke would become an issue for the picture. But perhaps the light source might just be a fake fireplace light display like the one I have her at home. Perhaps I over analyze. But regardless, This is still very festive while also being reminded of the original holiday chimney expert.

Great illustration and perspective! I like your use of foreshortening. The only thing is that you could have made the chest area a bit bigger. Judging by his current physique, his chest looks like it would actually be 50% smaller than his head. I know my one bat character Scruff is designed this way, so maybe I'm misjudging since I don't know the actual design of the character. However, to emphasize the chest area, perhaps bring the right shoulder out a litte more to give him some more slack in the thorax. Hope that helps!

Other than that, great illustration!