Downloadable Content

DLC or Downloadable Content are Characters, Costumes, S.T.A.R. Labs Missions, etc. that are available only through download or Pre-order.

Aquaman

 * Flashpoint (Season Pass or Flashpoint Costume Pack)
 * Blackest Night (Blackest Night Costume Pack 2)

Ares

 * Classic (Free with Zod Compatability Pack)

Bane

 * Luchador (Free with Batgirl Compatability Pack)
 * Knightfall (Lockdown Costume Pack [Wii U only] or rate iOS Injustice: Gods Among Us)

Batman

 * Arkham City (Wal-Mart Pre-order or Arkham City Costume Pack)
 * Blackest Night (Best Buy Pre-order or Blackest Night Costume Pack 2)
 * New 52 (Collector's Edition or Battle Edition or New 52 Costume Pack)
 * Batman Beyond (Lockdown Costume Pack (Wii U only))
 * Flashpoint (Free with Lobo Compatability Pack)
 * Red Son (Red Son Costume Pack 2)

Catwoman

 * Arkham City (Wal-Mart Pre-order or Arkham City Costume Pack)
 * Selina Kyle (Bad Girls Costume Pack)
 * Ame-Comi (Ame-Comi Costume Pack)

Cyborg

 * Teen Titans (Teen Titans Costume Pack)

Deathstroke

 * Flashpoint (Season Pass or Flashpoint Costume Pack)
 * Teen Titans (Teen Titans Costume Pack)
 * Red Son (Red Son Costume Pack 2)

Doomsday

 * Containment Suit (Free with Scorpion Compatability Pack)
 * Blackest Night (Blackest Night Costume Pack 1)

Flash

 * Blackest Night (Blackest Night Costume Pack 1)
 * Earth 2 (Earth 2 Costume Pack)

Green Arrow

 * The Arrow (Unlocked by Being Among the First 5,000 to Vote on an Injustice Battle Arena Match or by signing up for Injustice Updates via WB email newsletter. Later the skin was put on the XBL Market and PSN for free by NRS to show thanks for the support for Injustice since launch)

Harley Quinn

 * Classic (Bad Girls Costume Pack)
 * Ame-Comi (Ame-Comi Costume Pack)
 * Arkham City (Lockdown Costume Pack (Wii U only))

Hawkgirl

 * Blackest Night (Blackest Night Costume Pack 2)
 * Earth 2 (Earth 2 Costume Pack)

Joker

 * Arkham City (Wal-Mart Pre-order or Arkham City Costume Pack)
 * Tourist (The Killing Joke Costume Pack)
 * Final Confrontation (The Killing Joke Costume Pack)
 * Red Hood (The Killing Joke Costume Pack)

Raven

 * Teen Titans (Teen Titans Costume Pack)

Solomon Grundy

 * Red Son (GameStop Pre-order or Red Son Costume Pack)
 * Earth 2 (Earth 2 Costume Pack)

Superman

 * Red Son (GameStop Pre-order or Red Son Costume Pack)
 * New 52 (Collector's Edition or Battle Edition or New 52 Pack)
 * Blackest Night (Blackest Night Costume Pack 1)
 * Man of Steel (Man of Steel Pack)
 * Lockdown (Lockdown Costume Pack (Wii U only) or unlockable via ios or android app)
 * Cyborg Superman (Free with Zatanna Compatibility Pack)

Wonder Woman

 * Red Son (GameStop Pre-order or Red Son Costume Pack)
 * New 52 (Collector's Edition or Battle Edition or New 52 Pack)
 * Flashpoint (Season Pass or Flashpoint Costume Pack)
 * Issue #600 (Bad Girls Costume Pack)
 * Ame-Comi (Ame-Comi Costume Pack)

Zod

 * Man of Steel (DLC)

Red Son Storyline
The Red Son Pre-order Bonus provides an additional 20 Mission storyline where the player uses Superman, Wonder Woman, and Solomon Grundy in their Red Son skins.

DLC Character S.T.A.R. Labs Missions
The Injustice facebook page has confirmed 10 S.T.A.R. Labs Missions each for Lobo, Batgirl, Scorpion, and Zod. It costs $1.99 for the Missons, but Season Pass holders get them all for free.

Zombie Mode
Zombie Mode can be purchased separately or with one of the Blackest Night Costume Packs. It covers all the characters in dirt and gives them red eyes. They also start out with their costumes damaged.

Characters
According to the Season Pass, at least four characters will be released as DLC. Lobo, Batgirl, Scorpion, and Zod have been confirmed as the first 4 DLC characters for the first season pass. Martian Manhunter and Zatanna, the fifth and sixth DLC characters, have also been confirmed but not for the first season pass. The season pass also said that all DLC will be released by August 2013, though whether this truly means all DLC or only the DLC pertaining to this season pass remains to be seen.
 * Lobo
 * Batgirl
 * Scorpion
 * Zod
 * Martian Manhunter
 * Zatanna

Injustice DLC PSN Store Pages
Want to get some Injustice: Gods Among Us DLC? Here are some Links to get to the DLC Pages on the PSN Store (NOTE: All DLC is Not on this List!):
 * Season Pass
 * Lobo Pack | Character
 * Batgirl Pack | Character
 * Scorpion Pack | Character
 * Zod Pack | Character
 * Martian Manhunter Pack | Character
 * Zatanna Pack | Character
 * Bad Girls Pack | Skins
 * Teen Titans Pack | Skins
 * Flashpoint Pack | Skins
 * Killing Joke Pack | Skins
 * Red Son Pack #1 | Skins
 * Arkham City Pack | Skins
 * Blackest Night Pack #1 | Skins
 * Red Son Pack #2 | Skins
 * New 52 Pack | Skins
 * Blackest Night Pack #2 | Skins
 * Earth 2 Pack | Skins
 * The Man of Steel Pack - Superman | Skins
 * Ame-Comi Pack | Skins
 * Zombie Mode
 * Star Labs Missions

Injustice Xbox Marketplace DLC page
Injustice Xbox Marketplace Page