Zahhāk

In Persian mythology, Dahāka is treated as a proper noun, while the form Zahhāk, which appears in the Shāhnāme, was created through the influence of the unrelated Arabic word ḍaḥḥāk (ضَحَّاك) meaning "one who laughs."Despite the negative aspect of Aži Dahāka in mythology, dragons have been used on some banners of war throughout the history of Iranian peoples.

Aži Dahāka (Dahāg) in Zoroastrian literature Aži Dahāka is the most significant and long-lasting of the ažis of the Avesta, the earliest religious texts of Zoroastrianism. He is described as a monster with three mouths, six eyes, and three heads, cunning, intense, and demonic. In other respects, Aži Dahāka has human qualities and is never a mere animal.

In the Avesta, Aži Dahāka is said to have lived in the inaccessible fortress of Kuuirinta in the land of Baβri, where he worshipped the yazatas Arədvī Sūrā (Anāhitā), the divinity of the rivers, and Vayu, the god of the storm-wind. Based on the similarity between Baβri and Old Persian Bābiru (Babylon), later Zoroastrians localized Aži Dahāka in Mesopotamia, though the identification is open to doubt. Aži Dahāka asked these two yazatas for power to depopulate the world. Being representatives of the Good, they refused.

According to the post-Avestan texts, following the death of Jam ī Xšēd (Jamshid),[clarification needed] Dahāg gained kingly rule. Another late Zoroastrian text, the Mēnog ī xrad, says this was ultimately good because if Dahāg had not become king, the government would have been taken by the immortal demon Xešm (Aēšma). So evil would have ruled upon the earth until the world's end.

Dahāg is said to have ruled for a thousand years, starting from 100 years after Jam lost his Khvarenah, his royal glory. He is described as a sorcerer who ruled with the aid of demons, the daevas (divs).