These hags were once members of a coven who betrayed her sisters and was cursed as recompense. This curse cuts the hag off from her connection to her heritage and makes it impossible for them to form or join another coven until the curse is lifted.
Seeking aid these hags will often find patronage from other powerful beings and create an unholy bond.
A monster stat block and an encounter to boot.
Ninetoes82: 5E Adventures, Encounters and More 