In Mass Effect 3 for the PC, PS3, and Xbox 360, you can unlock the Salarian Infiltrator as a character to use in multiplayer, which is an agile combat character with some tech skills as well.
The Salarian Infiltrator is a rare card that you can unlock from purchasing any of the packs, however your chances are much better to get characters by purchasing Veteran and Spectre packs instead of Recruit packs.
Check out my other guide for more unlockable characters in Mass Effect 3 multiplayer.
Transformers: Rise of the Dark Spark – Stalker Logs Guide
The Elder Scrolls V: Skyrim Cheats, Tricks, Glitches, and Exploits
Borderlands 2 Achievements / Trophies Guide and Easter Eggs
WWE 13: How to Unlock Mike Tyson
Oddworld: Abes Odyssey – New n Tasty – Trophies List