The term Theriocephalus has an origin that derived from the Echdrarothrayun word Teryosethalií, which translates roughly to anthropomorphous. The term which survived over fifty thousand years eventually came to define the entire scope of all beastraces, of which the word was corrupted under Primordial Tongue and Old Tongue to give the modern word Theriocephalus; the Phoenix word was, under the Old Tongue, considered plural, and such the singular term came about around forty thousand years ago.
The origins of the Theriocephali are varied and often mysterious. The Ondarei Mharinis and the Ordnung are the oldest known beast races, and both are believed to have created their civilizations from scratch. Other races, such as the Terefah, are former Deiwes who were transformed into beasts by magical means. There are also races created by supernatural individuals, such as the Man-Serpents being creations of the Colossus of Sand Almonohuim, and the Pureblood Vampires being creations of the Simulacrum Zran Kar. Since ancient times, tensions between Theriocephali and Deiwes existed due to distrust and racism between one another, these still being present in modern times.
Arthropods are species possessing exoskeletons. Land-based races can appear similar to insects or arachnids in appearance, while marine races resemble crustaceans such as crabs or shrimp.
Avians are species with bird-like traits such as a beak, feathers and wings. Avian beast races vary greatly in behaviour and size, going from the man-sized and warrior-like Arkora to the gigantic and gentle Sohet.
Lacertilians are species who resemble wingless reptiles and lizards. Their skin is often made out of scales and plates, and they are most often found in the warmer regions of the world. Winged reptile folk are typically considered to be Lesser Kelodhres rather than Lacertilians.
Mammalians are species based on mammals, animals which can lactate to feed their young. The most diverse of the Theriocephali, they can be found all over Koldenwelt in large numbers.
Piscines are species possessing fish-like features such as gills and scales. They are commonly races that require water to breathe and therefore only live underwater, but fish races who can survive in the surface are not unheard of.
Indeterminate species are Theriocephali possessing traits of multiple kinds of creatures, and therefore cannot be classified with the others.