Mjolnir's origin in Marvel continuity mirrors the original Norse legend. The hammer is created when Odin's adopted son Loki cuts off the hair of the goddess Sif as part of a cruel jest, and, when threatened with violence by Thor, promises to fetch replacement hair from the dwarf smiths. Loki commissions the hair from the Sons of Ivaldi, and the obliging dwarves create the hair and a magic ship and spear as gifts for the gods. Loki is convinced that no one can match their workmanship, and challenges a dwarf named Eitri to make finer treasures. Eitri creates a golden ring and golden boar spear with magical properties, and then begins work on a hammer. Loki panics at the sight of the treasures, and, afraid he will lose the wager, transforms himself into a mayfly and stings Eitri's assistant on the brow as he is working the bellows for the forge. The assistant stops for a moment to wipe away the blood, and the bellows fall flat. As a result, the hammer's handle is shorter in length than Eitri had originally intended, meaning that the hammer could only be wielded one-handed.