The Malignant Matter, or simply Matter (マター Matā?), refers to the cancerous growth of Artificial Organisms that came to infest the Kurobe River in 2035. The most common forms of Matter have a reddish, fleshy appearance. Matter in its active state is extremely hostile to all living things and will attack and consume any organisms near its presence.

Community content is available under CC-BY-SA unless otherwise noted.