Brian co-starred in Universal's feature, The Five-Year Engagement, directed by Nick Stoller and produced by Judd Apatow and in the popular Canadian indie comedy, Lloyd the Conqueror. In the last year he has done guest spots on the sitcoms, The Big Bang Theory, You're the Worst, Guys With Kids and Anger Management. He also starred for three seasons in Comedy Central's popular show, The Sarah Silverman Program, and toured as one of the original members of the Comedians of Comedy.
Besides writing and performing on HBO's acclaimed Mr. Show, he has appeared in sitcoms such as Just Shoot Me, Seinfeld, NewsRadio, Californication, Everybody Loves Raymond and Friends. He also has an extensive resume in voice-acting including Aqua Teen Hunger Force, Adventure Time, Metalocalypse, Bob’s Burgers, Mission Hill and American Dad.
Brian has also appeared in several movies, including Judd Apatow’s Funny People, Rob Zombie's The Devil's Rejects, Fantastic Four: Rise of the Silver Surfer, Sex Drive, and Surfs Up.
He has written episodes of The Sarah Silverman Program and Metalocalypse (Adult Swim). He’s written for the popular sketch show, Human Giant and various specials and roasts including recent stints on the Oscars and The Comedy Central Roast of Rosanne Barr. In 2009 and 2010, Brian directed a video and a Comedy Central pilot for the hilarious hair metal band, Steel Panther.
In 2006 he released his first graphic novel, The Last Christmas, and his debut comedy album: Live in Nerd Rage. In 2009, Brian released his album, Fart and Weiner Jokes.
2013 also marked the release of a book co-written by Brian with Bob Odenkirk and David Cross called Hollywood Said No. He is also currently producing a Comedy Metal album with Scott Ian.