Mastiman is one of the Berber gods named in the Iohannis of Corippus, the Latin epic on the Byzantine wars against the Moors in the 540s CE. He belongs to the religious world of the Laguatan (Louata) confederation of Tripolitania and Cyrenaica, alongside the bull-god Gurzil and the war-god Sinifere. Corippus casts him as a grim, chthonic power associated with death and the underworld, before whom human sacrifices were performed, and the poet assimilates him to the Roman god of the dead. Modern scholarship treats him as a genuine indigenous deity of the eastern Berbers rather than a mere literary invention, even if the darker details are coloured by Corippus' hostile Christian perspective.