Sarah Cassidy (Earth-3434)

"Did you find out who Patient X was? I hate all this secrecy."

- - Sarah Cassidy to Batman

Doctor Sarah Cassidy is a psychiatrist of Arkham Asylum that was assigned to the case of serial killer Victor Zsasz. She was stalked and targeted by Zsasz after one of his escapes, but was ultimately saved by a timely intervention of Batman. Cassidy is a good friend with Gretchen Whistler, another Arkham doctor. She lives alone in a apartment on Gotham City with her cat, maintaining a good relationship with her best friend, Garianne. Cassidy works the night shift at Arkham's Medical Facility during the fourth week of every month.