Professor Jonathan Crane was bullied as a child for his bookish nature and scrawny figure. He became obsessed with fear and began to study it, eventually becoming a psychology professor in that field. He taught at Gotham University, but was fired for unethical experimenting. Professor Jonathan Crane then made a career out of villainy and became known as Scarecrow. Not only is he well-versed in fear, but Scarecrow uses it in his specialized toxins to bring out his victims' nightmares.