Sharp-sighted and extremely watchful. A mythological person with a hundred eyes.
Dictionary of Cliches by Eric Partridge, 1978.
The Wolf, Fenrir, was bound by a fetter called Gleipnir, made from six things: “the noise a cat makes when it moves, the beard of a woman, the roots of a mountain, the sinews of a bear, the breath of a fish, and the spittle of a bird.”
The Book of Imaginary Beings by Jorge Luis Borges, 2005.