The Beer Ghost is a unique recurring character who does not represent a country or other geopolitical entity.
First appearing as a doodle in the strip "I Love You," the Beer Ghost wasn't formally introduced until several strips later, when it terrorized Denmark, who called upon the shamanically-talented Greenland to deal with it. The ghost revealed its purpose--to steal beer--and thus made itself an enemy of booze-loving Nordics everywhere. There are no lengths to which it will not go to obtain its favorite beverage.
The Beer Ghost was the subject of a contest that took place in the fandom in Fall 2011. Fans were invited to create their best artistic interpretations of the ghost. The winner received tickets to that year's London Comic-Con, where Humon was attending and manning a booth in Artists' Alley. You can also buy beer ghost badges here