In Norse mythology, Gram is the name of the sword of Sigurd (Siegfried). He used it to kill the dragon Fafnir. It was forged by Weyland the Smith and originally belonged to his father, Sigmund, who received it in the hall of the Volsung after pulling it out of a log into which Odin had stuck it–nobody else could pull it out. The sword was destroyed and reforged at least once. After it was reforged, it clove an anvil in half. See Sigurd for more details on the story of Siegfried and Fafnir.