City of Terror

Synopsis
Botanist Pamela Isly becames Poison Ivy and manipulates Jonathan Crane aka the Scarecrow  to unleash his fear gas using her plants all over Gotham. But Crane also has plans for himself andd will show Batman, Ivy and Gotham the FEAR ITSELF

Post credit scene
We see that the fear gas had some repercussions on Harvey Dent

Cast
Jeffrey Dean Morgan as Bruce Wayne/Batman

Bryan Cranston as James Gordon

Terence Henry Stamp as Alfred

Christina Hendricks as Vicky Vale

John Hamm as Harvey Dent

Danny Glover as Lucius Fox

David Tennant as Doctor Johnathan Crane/The Scarecrow

Alicia Witt as Doctor Pamela Isley/Poison Ivy

Sequel to Dark Knight and part of the DC Cinematic Universe