If the omission of staple characters like Martian Manhunter in favour of the likes of Killer Frost didn't leave you a little perplexed, the coming Injustice Season Pass DLC looks set to challenge your expectations! Hot on the heels of Lobo [read more], we have confirmation that Batgirl is next up in the roster extension!

The somewhat surprising selection of Batgirl seems to open the doors to other rumored downloadable characters. General Zod and Mortal Kombat's Scorpion are speculated to be the remaining two characters featured in the four-character season pass.

Given the relative similarity to Batman and modern obscurity of the character, it's understandable that not everyone will be thrilled by the announcement. Representation of a diverse range of DC heroes was a bold promise early in promotion for the game, but it seems many favourites are fresh out of luck. Batgirl -- popularly voiced by Injustice actor Tara Strong in various cartoons -- joins an already Bat-heavy roster that includes fellow Strong Gotham girl, Harley Quinn, as well as Catwoman, Nightwing, Joker and Bane.

The concept of a female Bat-counterpart was first introduced to comics in 1956, beginning a long line of Batwoman and Batgirl incarnations. All indications suggest Injustice will feature Barbara Gordon -- the neice of Gotham's famous police commissioner, and recently restored Batgirl in DC's New 52 reboot.

Prior to the line-wide relaunch of the DC Comics roster, Barbara Gordon had gained greater popularity as the character Oracle. Inspired by the 1988 Alan Moore opus, Batman: The Killing Joke; Batgirl was paralyzed by a gunshot wound administered by The Joker. Wheelchair bound, she became the central operator for an intelligence network that was vital to Batman's operations throughout the 2000s, and included services to the Justice League and Birds of Prey.

Despite criticism for the callous, incidental plot that spawned the development, the Oracle years have become a definitive chapter in the characters history. As Oracle, the character was better differentiated from her origins as a female version of Batman -- a challenge NetherRealm Studios will no doubt take on as they attempt to sell the choice to fans hoping for more distinct playable characters.

Injustice: Gods Among Us DLC characters start rolling out May 7. Get a taste of things to come by checking out the Lobo gameplay trailer! Injustice is now available for PlayStation 3, Xbox 360 & Nintendo Wii U. Mortal Kombat Online recently reviewed the PS3 version [full story]. Discuss these stories and more on the DC Universe Injustice forum.