Hush

Is your doctor a killer? Well, This one is!

Real Name: Dr. Thomas Elliot

Arkham Origins: In Bane's lair, signs on the floor say that Dr.T Elliot had completed a surgery.

Arkham Asylum: Hush does not appear in the game, but you can see a list of the night shifts. Dr. Thomas Elliot's shift is on the list.

Arkham City: Hush is in the side mission: "Identity Theif" Batman sees a person with bandages wrapped around his head, he scans the area and finds a trail. That trail leads to a Witness, The witness says the killer looked like Bruce Wayne. When you scan the rest of the bodies, that will lead you to a lair. You listen to a recording, and then gates shut behind you. Hush then appears and talks with Batman. As they talk, Hush unwraps his bandaged-face to reveal a look-alike with Bruce Wayne.

"But you look just like..." -Batman

"Bruce Wayne? It took time of course, to find the perfect donors, to graft on the flesh and, finally, to lose myself in order to create... this." -Hush

Hush then says that Wayne will suffer, and Batman will not stop him. He leaves. Batman tells Oracle that he will find him tommorow.

Arkham Knight: Hush might be the Arkham Knight.