Amphisbaena
(Also Amphisbaena, Amfivena, Anphivena, or Fenmine)
Mentioned in the medieval bestiaries and even in Pliny’s Natural History, this creature is described as a two-headed serpent without a tail.
Its name originates from its ambiguous capacity to move in opposite directions, owing precisely to its possession of two heads.
It was also described as having eyes of tremendous brightness. It possessed a venom so deadly that for this very reason it was said to need two mouths in order to discharge it.