This is really similar to the tag Skinsuit, except that it just means wearing something, that resembles a human face. This is, of course, an excellent addition to the tag Hidden in plain sight, as it allows even hide something, that is worn over the head, mostly some kind of hood. An excellent story about this is Karen – Christmas Adventure by MonsterP63, and especially it’s sequel, Karen – New Year Adventure, where Karen wears this mask, to allow her to go outside, while being completely locked in an extreme fetish outfit.