Black Dog stalks travelers on the moors, and just hearing its footsteps can kill. A single glance from a basilisk is fatal. Wyverns -- two-legged dragons with wings -- attack castles and villages from the air. Hundreds of years ago, medieval scholars believed the world was filled with strange and terrifying creatures. They wrote about them in bestiaries -- collections of facts, myths, and stories about animals. Here are twenty-six creatures from those medieval legends, from the two-headed amphisbaena to the fierce ziphius, a water-owl that preys on ships and sailors. Detailed, dramatic paintings based on illuminated manuscripts will transport you to the Middle Ages -- when much of the world was still unknown and mysterious terrors haunted the night.