In Mass Effect 3 for the PC, PS3, and Xbox 360, you can unlock the Drell Adept as a character to use in multiplayer, which is a fast and nimble combat character with many biotic skills.
The Drell Adept is an uncommon card that you can get from purchasing any of the packs. Your chances are typically better to unlock characters with Veteran packs and Spectre packs over Recruit packs.
Check out my other guide for more unlockable characters in Mass Effect 3 multiplayer.