HBO has released a third "fan poster" for the second season of Game of Thrones (right; click for larger version). We believe it is meant to depict House Targaryen, or more specifically Daenerys Targaryen, "Mother of Dragons", the last member of the dynasty. The poster's tagline: "I will take what is mine."
See also our posts on the first fan poster ("The North Remembers") and the second fan poster ("The King can do as he likes").
Game of Thrones, adapted from the series of "A Song of Ice and Fire" epic fantasy novels by George R. R. Martin, returns on April 1st, 2012.