Scarecrow is a brilliant psychologist turned super-villain who fights Batman in Gotham City, specializing in techniques and chemicals that manipulate fear. Jonathan Crane was originally a well-respected professor, although he lost credibility when he obsessively took his experiments too far and descended into madness.
Batman was pursuing some of Scarecrow's henchmen when Green Lantern intervened and caught them much to Batman's annoyance who told him that he needed them interrogated not caught.
The Scarecrow first appeared in World's Finest Comics #3, created by Bob Kane and Bill Finger, published by DC Comics in Fall 1941. As the self-proclaimed "Fear Master", Scarecrow was an overly-obsessive and deranged professor of psychology in Gotham City, who was fired due his obsession to fear, an obsession that invaded his mind as a result of the bullying that he suffered in high school and his unfriendly family. He uses a variety of psychological tactics and experimental drugs to exploit the phobias and fears of his victims. Because of this, he has became one of the main members of Batman's rogues gallery.
In Nightwing and Robin, the Scarecrow was voiced by DC animation veteran actor Michael Rosenbaum, who apart of voicing the Scarecrow in the DC Animated Movie Universe, also voiced various characters in Bruce Timm's classic DC Animated Universe, like The Flash or Deadshot. In addition to playing other animated DC characters, Rosenbaum also played Lex Luthor in The CW's TV show Smallville.
The Scarecrow had an appearance originally written for Justice League: Throne of Atlantis, in which he was to be captured by Nightwing and Robin. Although the planned sequence was eventually dropped from the finished version of the film, the brief sequence ended up being what became the short Nightwing and Robin.