<p>Whether externally manifested by demons or internalized as the human flaws of greed, hatred, and hubris, the nature of evil is a driving question in Firdawsī’s famous <i>Shāh-nāma</i>. In dialogue with that work, this article takes up the far less famous poems of Īrānshāh ibn Abi’l-Khayr, <i>Bahman-nāma</i> and <i>Kūsh-nāma</i>, two epics that question the ontology of evil through their depictions of physical and ethical monstrosity. The <i>Bahman-nāma</i> begins with a prince’s desire to avenge the death of his father, an ostensibly admirable goal that devolves into bloodlust; the hero of the <i>Kūsh-nāma</i>, in contrast, is a hideous demon who commits unspeakable acts for thousands of lines, only to turn over a new leaf at the end of the poem. By following the journeys of these protagonists, Īrānshāh offers two portraits of evil that explore and complicate questions raised by Firdawsī, including the criteria for distinguishing hero from monster, and whether the fight against evil is necessarily good.</p>