Jonathan Crane is a psychopath known as the Scarecrow.
Jonathan Crane was bullied constantly as a child, leading him to be in a constant state of fear. He later graduated from colledge with a psycology degree, and went to work as a teacher at gotham university. He was fired for useing his students as test subjects for his study on fear. He then went to work at arkham asylum for the criminaly insane. He was also fired for the same reason. He then became the criminal known as the scarecrow and began to use the entire city as subjects for his reaserch.
He is a very sadistic individual, who enjoys the fear of others.
He has developed a gas called fear toxins that cause the inhaler to halucinate and see their worst fears manifest before their eyes. He is also very skilled in crane style kung-fu.