Two weeks before the March 19th opening of the exhibition, the phrase '3-19-08 THEY EXIST' was seen stencilled in the streets of Chicago. A week later, during the Annual St. Patrick's Day Parade, a band of unicorns walked the route. A team of volunteers followed the unicorns and handed out postcards to parade-goers. The postcard featured a grainy black and white image of a unicorn on Michigan Avenue. Print ads and bus shelters featured similar images of mythic creatures in immediately recognizable Chicago locations. Then, two nights before the opening, galloping unicorns and swimming mermaids were projected onto buildings along Chicago's famous Magnificent Mile. The night before the opening, the mythic creatures finally made their way to The Field Museum, where the unicorns and mermaids were projected on the enormous front façade of the museum. The next day, March 19th, Mythic Creatures opened and they really did exist.

Record crowds showed up for the opening week of Mythic Creatures. The overwhelming demand for tickets resulted in sold out showings of the exhibition. During the first 3 weeks, attendance was almost 10% above projection. And by the pivotal July 4th weekend, ticket sales exceeded goals by 33%. The exhibition continued to exceed expectations throughout its run, drawing large crowds of people curious about the science and legend behind some of the most fascinating creatures ever imagined.