From Aztec myth,  these creatures might be undead, or demons, or something else. They are the stars seen clustering around the edges of the sun during an eclipse. They come down to earth in times of great darkness, hunting only at night, possessing mortals but also tearing hearts out and eating them. Their queen is Itzpapalotl, aka Obsidian Butterfly, the incarnation of Sacrifice.

I chose to make them the ghostly, skeletal remnants of the spirits of dead stars...undead children of a queen of blood and death.

In Rega they might be called virgo inanis, or just void maidens. 

sheet here https://www.patreon.com/posts/68791137