Cornelius Stirk

History
Stirk, like Scarecrow, uses fear to get to his victims. Stirk has the ability to make other people see him as someone else, allowing him to get close to his victims. He operates under the delusion that he requires the nutrients and hormones from people's hearts in order to stay alive, and these are best prepared with norepinephrine by inducing fear in the victim prior to death.

In his first appearance, Stirk is released form Arkham Asylum, where he is confined to at the age of 16 for trying to kill a classmate, after being certified as sane - probably following his use of his psychic abilities on his doctors. He then subsequently stops taking his medication and begins his escalation into a serial killer.

Knightfall:
During the "Knightfall" storyline, Stirk works with the Joker in an attempt to kidnap Commissioner Gordon. However, tries to kill Gordon rather than kidnap him, much to Joker's dismay. Gordon hallucinates that Stirk is actually Batman as Stirk tried to kill Gordon with a knife. Batman stops Stirk, but Gordon is still screaming in fear. In order to capture Stirk, Batman is forced to leave leave a terrified Gordon with his wife, brings him to a hospital.

Batman: The Widening Gyre
Stirk recently made his return in Kevin Smith's storyline Batman: The Widening Gyre.

Powers and Abilities
Cornelius Stirk is able to cast a hypnotic aura which allows him to take on any face he chooses, generally a face that people will trust. He can also cause hallucinations through the use of telepathy.