Greg is a stand-up comedian and television writer and producer. A regular guest on The Howard Stern Show, Chelsea Lately, The Adam Carolla Show and The Joe Rogan Experience, his 2011 book, "Dear Mrs. Fitzsimmons" received critical praise from NPR and Vanity Fair.
Since 2006, Greg has hosted a radio show on Howard Stern's Sirius/XM channel and his own twice-weekly podcast, Fitzdog Radio. A regular on the Late Show with David Letterman, Conan, and Jimmy Kimmel Live, Greg also had two stand-up specials on Comedy Central and spent five years as a panelist on Best Week Ever.
As a writer, Greg won 4 Daytime Emmy Awards on The Ellen DeGeneres Show. He also worked on Lucky Louie, Politically Incorrect with Bill Maher and many others. He has created and executive produced pilots for VH1 and FX and served as head writer on The Chelsea Handler Show, The Man Show and Tiny Tonight.
Greg is the winner of "The Jury Award for Best Comedian" from The HBO Comedy Arts Festival and a Cable Ace Award for the game show he hosted called Idiot Savants.