Faust & Company specialise in masks, especially ones made out of neoprene, one of cosplay's best friends. This one is called "Dragon Skull", but that's just for copyright reasons: it's really just a nice and adult way for you to dress like a Pokémon.
It's a little more "realistic" than Cubone's version, but then, Cubone is a cartoon Pokémon, while the market for this are "realistic" human beings. So the change works.
They're handmade and expensive, so probably not for the compulsive, but if you're into casual cosplay (or just want to hang it on your wall and say you shot a Pokémon) you can get one here.
(via Fashionably Geek)
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