The Slouch Hat. The slouch hat is an object strongly associated with Australian identity. Corporal Matthew Walshaw from 4th/3rd Royal New South Wales Regiment adjusts his slouch hat before moving off to form up at the Rocks in Sydney, NSW.
This is another episode when Brian's book was mentioned. Stewie's phone number is (401) 555-0183. 401 is the actual area code for the state of Rhode Island, where Family Guy is set. Afuera is Spanish for outside. Lois mentions animal rights group PETA when Brian is speaking to the Griffins about animals rights.
In the special 30-minute 150th episode, Brian and Stewie (voiced by Seth MacFarlane) get locked in a bank vault overnight where they are forced to deal with each other on a whole new level.