Ja'far ibn Ali al-Hadi
Abū ʿAbd Allāh Jaʿfar ibn ʿAlī al-Hādī (Arabic: أبو عبد الله جعفر بن علي الهادي; 226-271 A.H., c. 840 CE – c. 885 CE), also derisively known as al-Kadhdhāb (Arabic: الکَذّاب, lit. 'the Liar') in Twelver Shi'ism, was the third son of the tenth Twelver Shi'a Imam, Ali al-Hadi. He claimed to be an imam and established his own sect of followers, to whom he was known as al-Zakī (Arabic: الزكي, lit. 'the pure one').