Hydros (legendary creature)
Encyclopedia
Hydros is a venomous snake from Medieval bestiaries
. Their poison caused the victim to swell up, and could only be cured with ox dung.
Bestiary
A bestiary, or Bestiarum vocabulum is a compendium of beasts. Bestiaries were made popular in the Middle Ages in illustrated volumes that described various animals, birds and even rocks. The natural history and illustration of each beast was usually accompanied by a moral lesson...
. Their poison caused the victim to swell up, and could only be cured with ox dung.