Herdbeast are domesticated ungulates used by more advanced civilizations of Lyon and possibly other carnivores to feed their often numerous population.
It is not known when animals started domesticating other animals or if the Herdbeast in question retain their sentience. Domesticating animals has certain side effects suggesting that they wouldn't however, particularly the reduction in brain size and tendency towards tameness and docility.
The Pale Ones are the only lyon society to do any large scale domesticating, though the practice is apparently common enough that other lyons who prefer wild-caught have heard of it even if they don't practice it. It is unknown if any northern Lyons domesticate there prey and their appears to a stigma attached to the practice as lyons who partake in are regarded as "fat and lazy" as their quarry.
Uropa and Shya have yet to be explored, however Endia seems to practice the keeping of herdbeast as many different species are on sale in the markets of the Imperial City of the Endian Empire. However, some lyons, particularly the Heathen Barbari, look down on farming and herding.