Zahhak
Zahhak is a figure of Iranian mythology, evident in ancient Iranian folklore as “Azi Dahak”. In the Avesta (the earliest religious text of Zoroastrianism) he is described as a monster with three mouths, six eyes and three heads, cunning, strong and demonic. But in other respect , Zahhak had human qualities and was never a mere animal. In post – Avesta Zoroastrian text, he was identified as an Arab. Zahhak killed Jamshid (king of Iran) and became the ruler. It is said to have ruled for a thousand years. Two snakes appeared on his shoulder as the result of kissing #### the evil on them. The two snakes craved brains of the youth for food, so everyday Zahhak’s spies would seize two men and execute them to feed the snakes. Kaveh fought against Zahhak and called people to support “Fereidoun” who was a young man and agrred to lead people aginst Zahhak.
Sources :
english wikipedia