The size would make it even more scarey...especially as a mask. Imagine something like that turning up at the front door, and a wee voice coming out of it saying "trick or treat?" :-D
That Looks great. If I was you, I´d seal it and make a Latex mold of it. Afterwards you could either cast a couple more and/or make some pretty decent Halloween masks.
As part of a Blogging challenge (Neopolitan challenge ..Blonde, brunette and redhead) I painted a 28mm redhead
The Blond - Brunette and more pics of the redhead HERE