Sheets 90/v and 91/r of the Madrid Code include drawings of strange mechanisms that are not linked to the treatise on mechanics and often have no explanatory text. Analysing them led to the reconstruction of mechanisms enabling a mysterious animal, a mechanical lion, to move robotically. The lion, a gift from Pope Leone X and the town of Florence, was taken to Lyon, in France; on July 12 1515, at the end of a surprising, magical walk before the King of France, Francis I, it stopped knocking some lilies over. It can be considered one of the first animal-like robots ever built.