It is said that there are two emanations of the mantra of the most terrible aShTha-mukha gaNDabheruNDa nR^isimha (AMGN)- a dakShiNa and vAma form. The right-handed form is said to lie in the text termed the bhIma-tantra which is a upa-tantra of the ananta-vijaya saMhitA of the viShNu-yAmala tradition. The left-handed form is said to like in the text termed vAmA-tantra which is also an upa-tantra of the ananta-vijaya saMhitA. Not much is know of the full extant of these texts ( if they survive in an degree at all they are obviously kept a close secret) but fragments relevant to ritual performance have been transmitted to those in the know. It is however clear that the left-handed vidya has propagated considerably in various guises. AMGN is said to have 8 heads of the leonine form with saber teeth, whereas two heads of the dinosaurian form (which are apparently concealed as per the vAma mantra). He has 16 hands with a garland of skulls and holds a chakra, trident, gadA, sword, bow and arrow, in addition to various other weapons. The mantra was narrated thus by mahAdeva to ishAnI when she embraced him and kissed him:
vedAnAm AdimaM chaiva ardhendhu-bindu-bhUShitaM |
pashchAd aShTAnanayeti pi~Ngordhva-kesha-vartmane ||
chaturviMshatinetrAya tadanu ShoDashabhujAya |
kR^iShNa-jImUta-vapuShe kapAla-mAlAneka dhAriNe ||
adhyAnta-krUra-chittAya ardhendu-daMShTriNe |
mAraya mAraya kAraya kAraya garjaya garjaya tarjaya tarjaya shoShaya shoShaya saptasAgarAn bandha bandha nAgAShTakAn gR^ihNa gR^ihNa shatrUn ha hA hi hI hu hu he hai ho hau haM haH cha astraM cha agni lalanA||
This formula’s origin in the brahminical viShNu yAmala tradition is supported by the use of the term “vedAnAM AdimaM” in describing the praNava in the mantra. This allusion to the praNava, the leader of the veda, has found its way into the chInAchArA tantras unaltered showing the direct lateral transfer of this mantra from the AstIka Hindu sources. The famed sadhaka of chInAchAra, matidhvaja shribhadra, became a knower of these mantras after acquiring them from a brahmin savant from Bihar. He journeyed to the court in Xanadu of the great Khan Kublai, the grandson of Chingiz Kha’Khan. The Kha’Khan appointed him to contruct a new script for the Mongol language. In course of this he initiated the Kha’Khan into the mantras of vama-AMGN and he became its practioner. From there it became popular in the secret realm of chInAchAra.