Demonlord Tagazin is a servant to Ixiataaga, the Deathlord of Ixia, and has existed for millenia -- presumably since the time of Agarash the Damned. The supernatural creature is sabre-toothed and jackal-like in appearance with creamy colored skin, a muscular body and knife sharp talons that extend from hairless paws.
Lone Wolf first hears tell of Tagazin during an encounter with Roark, Highborn of Amory, while pursuing the first Lorestone in The Kingdoms of Terror.
Lone Wolf does not encounter the creature for the first time, however, until years later, while he is attempting to reach the Drakkarim fortress of Torgar (and even then, only if his route takes him to the Isle of Ghosts). In the resulting confrontation, we learn that Tagazin is impervious to mortal weapons.
Tagazin attacks Lone Wolf during the events of The Deathlord of Ixia, a battle that ends when the Ixiataaga loses patience and sends both the Demonlord and the Kai Grand Master tumbling through a Shadow Gate that leads them to the Plane of Darkness. Here, Lone Wolf tracks and battles Tagazin twice more before finally destroying the creature, obtaining in the process the means to destroy Ixiataaga upon his return to Magnamund (unless he already has the Sommerswerd).