iconoclasm. I think a lot of people are uncomfortable with that. I understand that. It was very uncomfortable to write some of it." The novel is dedicated to his elder son, Milo, and to his grandfather, Adam. He revealed in an interview that he is writing a sequel to the book, to be titled The Sphynx of the Mississippi. He also stated in a 2006 interview with David Letterman that he intends the book to be the first in a trilogy. As of February 2019, Ferguson has produced no further novels, although he has published non-fiction. Ferguson signed a deal with HarperCollins to publish his memoirs. The book, entitled American on Purpose: The Improbable Adventures of an Unlikely Patriot, focuses on "how and why [he] became an American" and covers his years as a punk rocker, dancer, bouncer and construction worker as well as the rise of his career in Hollywood as an actor and comic. It went on sale 22 September 2009 in the United States. On 1 December 2010 the audiobook version was nominated for a Best Spoken Word Album Grammy. In July 2009, Jackie Collins was a guest on The Late Late Show to promote her new book Married Lovers. Collins said a character in her book, Don Verona, was based on Ferguson because she was such a fan of him and his show. Ferguson wrote a short story for In Sunlight or in Shadow (2017, Pegasus Crime), an anthology edited by Lawrence Block and featuring works inspired by the paintings of Edward Hopper (1882-1967). Block is a favorite writer of Ferguson's and appeared multiple times on The Late Late Show. On 10 October 2018, Ferguson announced his third book via Twitter, Riding the Elephant: A Memoir of Altercations, Humiliations, Hallucinations, and Observations which released 7 May 2019. Personal life Ferguson is a fan of Scottish football team Partick Thistle F.C. as well as the television show Doctor Who. He holds an FAA private pilot certificate, issued in 2009. He has five tattoos which include the Join, or Die political cartoon on his right forearm; a Ferguson family crest with the Latin motto Dulcius ex asperis ("Sweeter out of [or from] difficulty") on his upper right arm in honour of his father; and a Celtic cross with the Ingram clan motto Magnanimus esto (Be great of mind) on his upper left arm in honour of his mother.