It's too flat. I mean, there's no effect on it.
Also, the eyes. Where's the light come from? Dont try to c/p a cartoonish head, sir.
You need to fix the way you draw. Well it's not a bad head, but you need to give all of your skill in it, do not just c/p side by side. It's not a good thing to do in cartoonish art.
But that mask isn't that bad, those colors are nice there. Can be more better, dude. Keep trying.