NPC: A translucent mist
Long Desc: A see-through cloud floats in the air, moving slowly.

Floating lazily in the air, this mist is barely visible except from a
distance.  Getting closer, you can see a faint mass, something barely off-
white, only visible because of the dark nature of the room.  There is no
doubt that this mist would be completely invisible if it is exposed to
stronger light.  It doesn't appear to pose a threat to anyone, but it could
cause quite a problem just floating there.
It is a mist approximately 4'3" tall.

This NPC can be found in: A Disturbed Pyramid.