Smoke, Bone and Shadow

The Hounds of Smolder.

Conjured up out of smoke and shadow, given shape by the wind.

They do not have any true face and thus wear a mask made out of the bones of their prey, in particular the femurs.
Victims will find that their shadows slowly grow and show unusual shapes when stepping into darker places.
Unfortunately though, once these changes are noticed it is already too late.
Soon, the Hound will show itself to its victim and again appear at night, coming out of the shadows it was born from.
It will lower its mask and feast upon the victim, not just taking the flesh but its shadow and the darkness in its soul as well, to sustain its own existence.