 "Kilroy was here" is scrawled on one of the rocks Bugs strolls part  on the moon. This phrase originates from the graffiti used by GIs  around the world during World War II, and was found on fences and  buildings all over Europe. The origin supposedly lay in a US Army  sergeant who, after checking equipment, would write on it "Kilroy  was here". Usually, it was accompanied by a little peeking,  bulbous