The foul frog-demon Tsathogga (SA-thog-ha) cares less about the machinations of men and power than he does about obliterating light and life with the slow oozing sickness and decay that he represents. He is the vicious dark evil bubbling up from beneath the surface; the foul corruption at the heart of the earth. Tsathogga was one of the first Demon Lords summoned during the later days of the Uttermost War. This was not a good thing for the early human sorcerer's who summoned him.

Tsathogga makes his home on the plane of Tarterus at the mouth of the vast swamp of filth deposited by the river Styx as it flows out of the Abyss. Tsathogga's main form is of a colossaly-bloated humanoid frog with spindly, elongated limbs and fingers. His corpulent body exudes all manner of foul oils and fluids, which leak into the vile swamp in which he lies. He has positioned himself so that all of the slime and filth from the river Styx feeds into his gaping, toothy maw. He never moves and rarely speaks other than to emit an unintelligible shrieking. Tsathogga thoughtlessly commands a host of evil creatures - notably evil Slaad and his own vile frog race, the tsathar. Countless thousands of fawning tsather servants continuously bathe his body in fetid slime from the evil swamp, awaiting the divine bliss of being randomly devoured by him.

Tsathogga was first summoned at a place known now as the Swamp of Many Eyes in northern Ghinor. The Demon Lord's presence turned the entire swamp into a foul corruption and unleashed thousands of his vile frog race, the tsathar onto Wearth. Tsathogga was quickly banished back to Tarterus but the tsather remained behind. For a brief period during the last hundred years of the Uttermost War and the early centuries of the Rule of the Sorcerer Kings the tsathar spread throughout Wearth building secret temples. In the early days of the World Empire most of these temples were found and destroyed. His followers hatred of light and lack of human worshippers (though there have been notable exceptions) mean that he is little known to the surface races of today.

A few words on the tsathar (suh-Thar). These vile creatures resemble upright humanoid frogs. They have had little contact with surface-dwelling races, preferring to make their lairs deep underground or in dark swamps. When they lair above ground they are nocturnal. Some few surface-dwelling tsathar have joined cults of assassins. Nearly all tsathar worship their foul, slime-covered demon frog-god Tsathogga. Sages (correctly) speculate that tsathar are prime material relatives of the chaotic Slaad. They bear a resemblance to gray Slaad, and in fact groups of tsathar are often led by chaotic evil gray Slaad sorcerer-priests of Tsathoga.

Tsathogga has few organized centers of worship and no standardized holy symbol - each worshipper choosing their own way to best depict his deific vileness. There is a great hatred between the followers of Tsathogga and those of Wastri. Both groups are known to fight to the death on the discovery of either side.