Umbra is a type of matter which can bond with certain proteins and molecules to create life. Umbrology is the study of Umbra-based creatures, and is analogous to biology. Umbra-based creatures (or Umbral Creatures) almost always have hyperdivergent phenotypes among their kind.
Umbra is made up of smaller black crystalline particulates known as aberrant cells. These unique structures constantly undulate and move at high speeds. Aberrant cells are in the shape of dodecahedrons, and can combine into grid-shaped patterns. These patterns can then form lesser microbial organisms, which consume smaller proteins and molecules and eventually become macroscopic.
These lifeforms, eventually congeal into the modern day Umbra we know today. Umbra is a thick black sludge made up of these microscopic aberrant cells, and from this Umbral sludge arises many creatures. How, or why, creatures and organism arise from this Umbral sludge is beyond us.
Umbral organisms consist of a biological casing, skin, flesh, etc., with an inner shade made of pure Umbra. When an Umbral organism expires, their shade exits this biological casing and is allowed to roam the Prime Material Plane freely, until it reforms. If the shade is destroyed, the Umbral organism is completely extirpated.
The lifeforms that crawl from the sludge are not part of any species, completely unique and unrelated to all others. However, eventually creatures managed to reproduce with others who are compatible, and eventually their kin reproduce with more compatible creatures, and create true species as we know them.
Umbral beings cannot die of old age, and therefore some from the very beginning, not part of any taxonomic classification still exist.
Umbra is an extremely unique form of matter, which can create myriad forms of life in just a few generations. Because of this, our research division has elected to try and use it to create effective weapons, workers, and soldiers.