Brian Griffin

Brian is largely treated as a person, and his human traits are neither explained nor much remarked upon. He is often the most level-headed member of the family. He and Stewie argue and humiliate each other constantly yet depend on one another. Brian drinks heavily and smokes, and after a stint as a sniffer dog he developed a cocaine habit that ended in rehab. He attended Brown University, as shown in "Brian Goes Back to College", but left one course short of graduating. Stewie enlisted them both in the army in "Saving Private Brian", making Brian an Iraq War veteran. He has a human son, Dylan. Brian is an atheist and a liberal who supports legalising marijuana and gay marriage. Despite his intelligence he still fears the vacuum cleaner and gets excited when dog food is shaken.

Brian is an unemployed aspiring writer, a trait said to reference Snoopy from Peanuts and to reflect a younger MacFarlane. His lack of success is a recurring joke. In "Play It Again, Brian" he wins an award for an essay he later admits he plagiarised. His novel Faster Than the Speed of Love, begun in "Movin' Out (Brian's Song)", is finally published in "420" with Carter Pewterschmidt's help, is savaged by critics and sells no copies. A television script he writes in "Brian Griffin's House of Payne" is picked up by CBS and turned into a broad comedy. In "Brian Writes a Bestseller" a self-help book of mostly blank pages becomes a hit until an interview on Real Time with Bill Maher ends it. In "Brian's Play" his stage play is overshadowed by one written by Stewie.

Brian is based on Steve, the dog in MacFarlane's student short The Life of Larry and its 1997 sequel. Representatives of 20th Century Fox saw the shorts and asked MacFarlane to develop a series. They gave him $50,000 for a pilot, which he has described as around a twentieth of a normal pilot budget. He created the Griffin family in three months. MacFarlane voices Brian with his own normal speaking voice, alongside Peter, Stewie and Quagmire. William H. Macy auditioned for the role without success. In "Road to the Multiverse" the Japanese actor Kotaro Watanabe voiced Brian in a scene set in a universe where everything is Japanese. MacFarlane has said Brian is his favourite character to play, because he feels most comfortable in the role, and has noted his own similarities to the character.

In "Life of Brian", the twelfth-season episode, Brian is hit by a car while setting up a street hockey net and dies at the veterinary clinic. Stewie, having destroyed his time machine, cannot rebuild it, and after a month the family takes in a new dog, Vinny. Fans responded angrily, with threats of boycotts and a flood of messages to the show's social media accounts. A Change.org petition addressed to MacFarlane gathered more than 120,000 signatures. In "Christmas Guy", two episodes on, Stewie meets a past version of himself who has travelled forward in time. While Vinny distracts the visitor, Stewie takes his return pad, goes back and saves Brian, erasing that version of himself from history. MacFarlane afterwards said on Twitter that the death had never been intended to be permanent.

Ahsan Haque of IGN reviewed Brian positively and called his pairing with Stewie a winning formula for the show. Reviewing the seventh season, however, Haque wrote that the character had been misused as a mouthpiece for the writers' politics. Ramsey Isler, reviewing the eighth season, said Brian had gone from voice of reason to pretentious loser. At The A.V. Club, Emily St. James described Brian as the show's best and most developed character. IGN placed him second, behind only Stewie, in its ranking of the top 25 characters from the show. The same site ranked his fight with Stewie in "Patriot Games" fifth among the show's fights and gave three of his songs places in its top ten musical moments. Later reception has been more mixed, with criticism of his self-righteous and hypocritical behaviour.