Stories of Gotham City
F.E.A.R. is a hallucinogen drug, developed by Dr. Jonathan Crane, aka. The Scarecrow. It is a very powerful dissociative, that induces an anxiety status and alters the perception of its victims that increases until the victim literally die of fear. It also makes the victim highly susceptible to suggestions that tend to form very detailed hallucinations.
It is composed form several natural drugs and chemicals and is highly potent. It can be administered through the skin, the stomach and inhaled.