The Icon of the Lich King is the racial crest of the Scourge, and symbolizes their cold, evil leader The Lich King, and his control over the Scourge. The sword in the center is the sword of their leader, the Lich King, and is called Frostmourne. The frozen skulls with arrows though them symbolizes their death and then rebirth. The frozen hammers resemble that the Scourge only resolve their conflicts or differences with war and violence. The fact that everything in the picture is frozen symbolizes their cold, dead bodies.