Galifianakis illustrated the book Tell Me About It: Lying, Sulking, Getting Fat ... and 56 Other Things NOT to Do While Looking for Love, authored by Hax in 2001.

In 2014 he co-authored The Art of Richard Thompson with David Apatoff and Bill Watterson[3] In May, 2017 – while also serving as the host of the 71st annual National Cartoonists Society Reuben Awards – Nick was awarded a Reuben in the category of Newspaper Panel Cartoon for his work on "Nick & Zuzu.

[11] Galifianakis's earlier work prominently featured his pit bull, Zuzu, who died in August 2010.

[12] Zuzu was named after a character in the film It's A Wonderful Life, the daughter of George Bailey – who gave him flower petals to carry in his pocket.

"[13] In an August 2010 The Washington Post tribute to Zuzu, Galifianakis wrote: "she died a week short of 13, rendering me more human than I had ever cared to be.