Black-winged Ones
entityNigripennes nemorum—Killers out of the haunted wood
Mysterious winged allies of the swamp cult, which the captured worshipers said had done the ritual killings, coming to them from their immemorial meeting-place in the haunted wood.
The captured worshipers all denied a part in the ritual murders, and averred that the killing had been done by the Black-winged Ones, which had come to them from their immemorial meeting-place in the haunted wood.
Of those mysterious allies no coherent account could ever be gained; they are known only from the prisoners' testimony.
Haunts
Sources
Every fact above traces back to the text.
“All denied a part in the ritual murders, and averred that the killing had been done by Black-winged Ones which had come to them from their immemorial meeting-place in the haunted wood. But of those mysterious allies no coherent account could ever be gained.”
The Call of Cthulhu (1928) — Chapter 2, The Tale of Inspector Legrasse