Sony has leaked some new details about the Batman: Arkham Knight's exclusive content for PS4. According to Playsation.com, Sony's console will have the "Scarecrow Nightmare Pack" Their discription:
"Gotham falls victim to Scarecrow's fear toxin, transforming the famous city into a twisted, hellish nightmare in the Batman: Arkham Knight Scarecrow Nightmare Pack.
Tear through the city in the all-new batmobile and face off against a towering vision of Scarecrow and his undead army as they spread terror on the streets, available exclusively on Playstation 4."
Source
"Gotham falls victim to Scarecrow's fear toxin, transforming the famous city into a twisted, hellish nightmare in the Batman: Arkham Knight Scarecrow Nightmare Pack.
Tear through the city in the all-new batmobile and face off against a towering vision of Scarecrow and his undead army as they spread terror on the streets, available exclusively on Playstation 4."
Source