DC Universe: After the Fall
"Physical power, technology, weapons. Meaningless. True power is in fear."
Taunted and bullied in his youth, Jonathan Crane vowed to overcome his fears through the study of psychology and biochemistry. Despite displaying no small amount of genius in his field, he was eventually kicked out of his university for experimenting on human subjects. However, Crane had already become obsessed with the power that the fear he instilled in his patients gave him. Crane adopted the identity of the Scarecrow and armed himself with a specialized fear-inducing gas that made a person’s deepest fears become frighteningly real. His ensuing criminal reign of terror secured his place as one of Batman’s most psychologically dangerous foes.
Over the years, Crane’s obsession with terror grew to the point where he could no longer function if not surrounded by fear. He continued to advance his science, developing more and more powerful incarnations of his fear toxin, ever trying to cause Gotham to tear itself to shreds.
After Brainiac’s defeat at the hands of Lex Luthor and Batman, Crane vanished for a number of years. Over that time, a series of mysterious broadcasts, nothing but series’ of numbers, were occasionally heard on unused Gotham radio waves, which most conspiracy theorists believed to be from the Riddler. However, recently the GCPD discovered that these were in face messages from Scarecrow buried under multiple levels of ciphers and code. These messages referred to an upcoming event, but gave no details. The same day the GCPD cracked the code, Scarecrow finally struck.
Unleashing a gas that was a mixture of his own Fear Toxin and Jervis Tetch’s mind control techniques, Scarecrow launched a massive terror attack near Gotham Harbor, resulting in over a thousand deaths. Since then, Scarecrow’s reign of terror has held steady, and he had consumed multpiple gangs in his consolidation. He has also personally defeated the Red Hood several times, and at the moment seems to be perhaps the most potent threat to Gotham City.