Feral Demons are mysterious mutations which appear in Fallout: Equestria - Operation Flankorage
Feral Demons are mutated ponies which live in the zebra tunnels underneath the forest to the south of Flankorage. Feral Demons are distinguished by their long hair, clawed paws and red eyes. They seem to live exclusively in the zebra tunnels and are able to dig through them with ease. Travelling in packs, these creatures are animalistic in nature, attacking on instinct. They do not show up on a normally calibrated PipBuck's map and cannot be targeted by S.A.T.S.
They reproduction through infection of a virus, the exchange of bodily fluids being the most common. The only exception to this is saliva. However their numbers are kept low by the fact that they kill most of the ponies they encounter. BARON states that it had contributed to the creation of the virus, however just what his role was in its creation has yet to be revealed.
Ocher Bullion has been infected by a bite and is slowly turning into one of these. Though he greatly resembles one now, he still has his rational thought. BARON has stated that there is cure to the virus and they are currently travelling to the Canterlot MAS Hub to get it.
Feral Demon is a fan nickname, however they have been called both ferals and demons within the story itself.