Daeva
Daeva
In the Zoroastrian religion, a daeva is a demonic and destructive being. Daevas are combated by the ahuras who help to uphold the moral law.
In 1.16 Shadow, Meg summons the daevas using a black altar. Caleb tells Dean that the Zoroastrian symbol (The "Z") is a sigil for a Daeva and is "very, very old school, like two thousand years before Christ."
Dean says that Daeva "translates to 'demon of darkness.' Zoroastrian demons, and they’re savage, animalistic, you know, nasty attitudes—kind of like, uh, demonic pit bulls."
Meg has some control over the daevas, but when her black altar is destroyed, the daevas turn on her and pull her through a window. She falls from the building.
They are invisible to the human eye except for their shadows. When they attack the Winchesters, Sam calls them "Shadow Demons" and repels them using a flare gun - making it impossible for shadows to exist in the room with that much light.
