Below is a run down of the available Batman Arkham Origins Unlockable Skins,
First up the free ones, you can switch Batman’s skin in the Batcave’s Batsuit Chamber at any time,
How To Unlock: This is your starting Batman suit
Batman Blackest Night Skin
How To Unlock: Earn Prestige in Multiplayer.
Batman Dark Knight Skin
How To Unlock: Complete all Dark Knight Challenges.
Batman Injustice Skin
How To Unlock: Earn all Challenge Mode Medals.
Batman New 52 Graphic Skin
How To Unlock: Capture every Most Wanted target in Story Mode.
Please note, collecting all the Enigma Packs (Noel costume skin below) is also needed to complete the Most Wanted database for Enigma.
Batman Noel Skin
How To Unlock: Find 100% of the Enigma Datapacks in Story Mode.
Batman One Million Skin
How To Unlock: Register and link a WB Games ID account.
Now the paid for skins
Brightest Day Batman Skin
Gotham by Gaslight Batman Skin
How To Unlock: These exclusive skins are available to those who buy the “Batman Arkham Origins – Season Pass” on your system’s online store.
Earth-2 Bruce Wayne Skin
The Long Halloween Skin
Earth-2 New Skin
Batman Thrillkiller Skin
Knight of the Round Table Skin
1989-2006 Classic Tim Drake Robin Skin
How To Unlock: Buy the “Infinite Earths Pack” on your system’s online store.
First Appearance 1939 Skin
Red Son Skin
New 52 Skin
Blackest Night 2006-2008 Tim Drake Robin Skin
How To Unlock: Buy the “New Millenium Pack” on your system’s online store.