Duldul, a beloved she-mule of the Prophet Muhammad and ʿAli b. Abi Talib (d. 661), fourth caliph and Muhammad's son-in-law, was a venerated riding beast in early Islamic tradition. The article argues that Duldul reflected the transmission of political authority and became a tool of legitimation for hadith compilers and medieval Muslim writers to use, contest, and navigate an emergent Shiʿa-Sunni rift. Exploring the responsive relationship between hadith construction and the Shiʿa-Sunni polemic, the article first analyzes three literary genres—maghāzī, hadith, and sīra—to describe Duldul and her role in early Islamic history. Second, the article examines the writings of al-Jahiz (d. 868) and al-Damiri (d. 1405) to understand medieval Muslim attitudes toward Duldul and she-mules in general. By taking Duldul more seriously as a historical actor, we can gain deeper insight into the disputes over Muhammad's legacy in medieval Islam.