Katha-Hem was the third of the Ogdru Hem to be set loose upon the world, and by far the most powerful. While Sadu-Hem was foretold to bring about the plague of frogs, the arrival of Katha-Hem was an indication that the world would begin to change.
Summoned out of the ether by the occult rituals of the frog monsters and the Zinco Corporation's Mr. Pope, (also known as the Black Flame) Katha-Hem towered as large as a mountain and began marching across the Midwestern United States. Atop a tripod of spidery legs, Katha-Hem resembled a twisted, tentacled tree, its canopy an inferno of hellish blue fire, and numerous green-toothed maws lining its trunk. American artillery failed to make a dent in the mammoth creature, while any humans who ventured too close were turned into monsters by a strange green gas emitted from its body. Just as the President was about to resort to a nuclear strike, the B.P.R.D.'s Liz Sherman managed to burn Katha-Hem to ashes, using an ancient artifact that mysteriously amplified her powers a thousand times.
Katha-Hem's destruction (and the apparent mass suicide of the frog monsters) appeared to bring the plague of frogs to an end.