Gleipnir

Two chains failed. The third, in the telling, was made by dwarves from six impossible things — the sound of a cat's footfall, a woman's beard, the roots of a mountain, the sinews of a bear, the breath of a fish, the spittle of a bird — and came out soft as a ribbon. Fenrir was not stupid. He agreed to test it only if one of the Æsir would place a hand in his mouth as surety. Týr did. The ribbon held. Týr lost the hand, and is described as having known he would.