Abū Yazīd Mukhallad ibn Kayrād (Arabic: أبو يزيد مخلد بن كيراد; 873 - 19 August 947), ad-Dajjal, nicknamed Ṣāhib al-Himār "Possessor of the donkey", was a Kharijite Berber of the Banu Ifran tribe who led a rebellion against the Fatimids in Ifriqiya (modern Tunisia and eastern Algeria) starting in 944. Abū Yazīd conquered Kairouan for a time, but was eventually driven back and defeated by the Fatimid caliph al-Mansur.
Abū Yazīd's father Kayrād was a trans-Saharan trader from Qastilia, where he was born; he grew up in Tozeur. Abū Yazīd inclined towards the Nakkariyyah branch of Sufri Kharijism. After he grew up, he went to Tahert, the Rustamid capital and the main center of (Ibadi) Kharijism in the Maghreb of the time and took up teaching.
However, in 909 the Ismaili Shī‘ī Fatimids conquered the Rustamids and soon after the Sufri state of Sijilmassa to the west. Abū Yazīd moved to Tiqyus and began agitating against Fatimid rule in 928. When the Fatimid al-Mahdi died in 944, Abū Yazīd launched a rebellion in the Aures mountains and declared himself Shaykh al-Mu'minīn "Elder of the Believers", seeking aid from the Umayyads of Andalus.
Early in his rebellion, Abū Yazīd was given a gray donkey which he used to ride, for which he received the nickname "Possessor of the donkey". Abū Yazīd also habitually wore a short woolen jubba cloak and with his conspicuous frugality, he recalled the Kharijite imams of Tahert and Sijilmassa.
Abū Yazīd was initially notably successful. He took Baghai, then Tebessa, Medjana, and several Tunisian cities including Béja, where he is said to have massacred the civilian population. The population of Tunis threw out their governor and let Abū Yazīd in. By the end of the year, he had conquered Kairouan itself, dealing several severe defeats to the Fatimid armies.
In 945, as Abū Yazīd besieged Sousse, Caliph al-Qā'im died and was succeeded by his son al-Mansur. Under al-Mansur's leadership, the Fatimid forces recovered their position, first breaking the siege of Sousse and then driving Abū Yazīd's forces out of Kairouan back into the Aurès Mountains. In 947, the Fatimids finally defeated them in the Kiyana Mountains near what later became Qalaat Beni Hammad.
W. K. R. Hallam, in "The Bayajidda legend in Hausa folklore", Journal of African History VII.1 (1966), argues that the Hausa culture hero Bayajidda represents a folk personification of the supporters of Abū Yazīd who fled North Africa after his defeat.