There’s an interesting story at The Smithsonian’s Past Imperfect blog regarding the peculiar history of the mythological basilisk. Those of you who spent your teenage years playing Dungeons & Dragons in your basement might already know what a basilisk is. However, for the rest of you, here’s a description:
The basilisk remained an object of terror long after the collapse of the Roman empire and was popular in medieval bestiaries. It was in this period that a great deal of additional myth grew up around it. It became less a serpent than a mix of snake and rooster; it was almost literally hellish. Jan Bondeson notes that the monster was “the subject of a lengthy discourse in the early-13th-century bestiary of Pierre de Beauvais. An aged cock, which had lost its virility, would sometimes lay a small, abnormal egg. If this egg is laid in a dunghill and hatched by a toad, a misshapen creature, with the upper body of a rooster, bat-like wings, and the tail of a snake will come forth.