"This episode of the dragon is in fact a very late development, which cannot be traced further back than the twelfth or thirteenth century. It is found in the Golden Legend (Historia Lombardic of James de Voragine and to this circumstance it probably owes its wide diffusion. It may have been derived from an allegorization of the tyrant Diocletian or Dadianus, who is sometimes called a dragon (ho bythios drakon) in the older text ..."
I was wondering what exactly is meant by "bythios". My Greek dictionary says "in/from the depth". A dragon from below? Underworld? Leviathan from the depth of the sea?