Shades of Mortal Kombat vs. DC Universe right there...

Source: YouTube

Neatherealm announced that Scorpion, the popular Mortal Kombat ninja, would be joining the cast of Injustice: Gods Among Us. The character had been rumored as a DLC character. Jim Lee redesigned Scorpion's costume for the event, which can be seen in the video below.

It's popularly believed that Zod will be the fourth playable DLC character, but the teaser above hints that Martian Manhunter might appear as a playable character instead. Ed Boon has stated repeatedly that they made add additional DLC characters to Injustice if demand is high.