All sorts of strange animals bounded through medieval minds. There were the blemmyes, beings who wore their faces on the front of their torsos, and the bonnacons, bullish beasts that fought their foes with fireballs of dung. There were sea monks and mermaids and mermen, not to mention the many species of sea serpents. And while barnacle birds fell from trees as if they were fruit, some mythical sheep were thought to be suspiciously strong thanks to the wriggling worms that sat inside their brains…