According to ABCnews.com, Marc Hartzman is "one of America's leading connoisseurs of the bizarre." His passion for the unusual began at an early age, influenced by Ripley's Believe It Or Not and the annual Guinness Books. In addition to his books about ghosts, Mars, Oliver Cromwell's embalmed head, weird things on eBay, sideshow performers, and unorthodox messages from God, Hartzman has written for Mental Floss, the Huffington Post, AOL Weird News, and Bizarre magazine. He's discussed oddities on CNN, MSNBC, and the Travel Channel's Mysteries at the Museum. He also runs WeirdHistorian.com. When not writing about life's peculiarities, Hartzman writes about various goods and services in the advertising industry.