History
Jane Doe first appeared within the pages of Arkham Asylum: Living Hell. She is an inmate at Arkham Asylum, and a notable serial killer.
She observes and gets to know people before killing them and taking their identity for herself, trying to find one she could be happy in. She does not limit herself in her choices by gender or occupation, based on her observations able to perform the job requirements of anybody she becomes, simply by forcing her mind to become to them.
In arguably her own words, albeit in the third person while still under the influences of the Anne Carver identity, "Jane is a cipher. She's incomplete. Her life is empty, so she covets the lives of others. She takes their lives so she can have their lives."
Prior to the events of "Arkham Asylum: Living Hell #1" she had usurped the identity of Arkham psychiatrist "Anne Carver," and was giving psychological evaluations of other inmates. But she was defeated by Batman before she could murder billionaire criminal Warren White and assume his identity. In "Arkham Asylum: Living Hell #3", she takes the identity of a security guard "Wrigley" and releases the criminal "Doodlebug" from his cell.
In "Arkham Asylum: Living Hell #6", she locks White in a freezer, where his skin bleaches, and his ears, nose and lips fall off, completing his transformation into the Great White Shark. Later, after escaping, he confronts her and strips her of his identity.
Her latest appearance to date is in Streets of Gotham where it was revealed that she'd lost her face in an accident several years ago. She soon begins developing an obsession with "Bruce Wayne" who is actually his childhood friend and sworn enemy, Thomas Elliot aka Hush.
She takes the place of Wayne's new secretary and then cuts off Hush's Bruce Wayne face in hopes of becoming Bruce Wayne herself but the real Batman catches her and Hush in the act.
Powers and Abilities
Jane possesses a vastly above average ability to imitate others. Not only can she perfectly copy body language and speech patterns, but is a good enough judge of character to after observation nigh impeccably think the way somebody else thinks.
Equipment
Jane Doe has been shown to carry numerous different items. Besides all of the equipment of whichever person she's adopting the identity of, she carries a tape recorder to help her mimic voices. On one occasion, she nearly escaped from Arkham Asylum with a collection of body parts she had kept in unknown locations. The emergency exit required a fingerprint scan, a retinal scan, and a voice I.D., and she simply procured Dr. Anne Carver's severed hand, eyeball in a jar, and a voice pleading not to kill her on her tape recorder. She was immediately stopped by Batman however.
Weapons
Known to carry conventional and convenient weapons. A knife or a gun. Whatever gets the job done.