To a very strange lizard, found by the gardener of the Belvedere, he [Leonardo] fastened some wings with a mixture of quicksilver made from scales scraped from other lizards, which quivered as it moved by crawling about. After he had fashioned eyes, a horn, and a beard for it, he tamed the lizard and kept it in a box, and all the friends to whom he showed it fled in terror.The Life of Leonardo da Vinci (from The Lives of the Artists)