Zahhak is an evil character in Iranian mythology.
In this myth, which is mentioned in the Shahnameh, when Zahhak reaches the kingdom, he is tricked by Ahriman, whose kisses turn into monstrous snakes that come out of the king's shoulders. Feeding the snakes eating young people's brains, he sacrificed many youngsters. The Serpent King is infamous in the world for his treachery and cruelty. He rules for a thousand years until a brave Iranian youth named Fereydun comes to power and gathers an army to defeat the cruel king. Fereydon defeats Zahak and does not kill him. The noble Fereydon imprisons him in Mount Damavand.
In this illustration, I have portrayed the snakes in the shape of brains, which represent the brains eaten by Zahhak. The mountain where Zahhak is imprisoned is the devil who deceived him and the skulls that chained him.