Saving Private Brian is episode 04 of family guy season 05. It was originally aired on November 5, 2006.
After Chris is approached by an Army recruiter, Brian goes to the headquarters to give him a piece of his mind, but Stewie tags along and gets them both enlisted in boot camp. The two make it through training with no help from Sergeant Angryman and end up in Iraq, where they try everything possible to get an honorable discharge. Meanwhile, at home base, Chris joins a Goth rock band and their hit track is “Evil, Evil Monkey”.