The composition of this planet is said to be made of porous and absorbent rock. The water of the atmosphere is mixed with sulfur dioxide, producing deadly acid rain.

The surface of the planet has long-been eroded by the corrosive atmosphere and it is now a group of tightly-packed and jagged peaks resembling an immense and deadly jaw. The effect is completed by two caves in the equator of the planet that resembles an opening mouth. These caves have been carved by the acid water coming down from the toxic atmosphere and have penetrated deep down under the surface of the planet, reaching even to the core.

A few life-forms have evolved on the planet, using the caves as a safe refuge from the hostile conditions. Entire jungles are said to be located deep inside Deysum III, and the tallest of the trees can be seen sprouting marvelously from the caverns of this world. These trees have developed thick bark to resist the corrosive properties of the air.