These beings-- of extra-terrestrial origins, have been acknowledged to reside on various places in Hillys, and often occur in different shapes. They usually appear as an odd mix of floating bones and dark flesh that resembles the form of a spider. They have a pearl stuck in the middle of their bodies. Some are also rooted to the ground with dark root-like tentacles, these may be infant Spirit Eater, who lose their roots later in life (It may be a very quick process for a DomZ to grow from an infant to a mature stage, taking less than a few hours).
The pearl they possess (turned green by their influence) is the source of their power and life, as well as their weak spot. They can use it to sap the energy of an organic entity, as a way of offensive means, and to give life to inanimate objects, such as mechanical parts. They can also call upon reinforcements and cause skeletal arms to sprout out of the ground and swipe at enemies (only during their root stage). The only way to defeat them is to hit the pearl until the DomZ disintegrates. When they die, they usually wiggle their legs around and shrivel up like spiders in pain.
The DomZ in general have the power to corrupt other beings if they are in their presence for too long, shown by DomZ-like growths appearing on the infected's skin. The soldiers of the Alpha Sections are the first to undergo this transformation. When they remove their helmets, their faces are revealed to be distorted with tentacle-like organic matter, and are no longer recognizable as human beings. Double H also becomes infected with a DomZ spore later in the game, though he is cured by the IRIS Network who apparently developed an antidote against it. The infection seems rather painful (as evidenced by Double H's experience), though the effects could be different for each individual.