They are similar to pre-war Sika in physiology, with the same build and figure. Radiation the changing needs of the post-war world has forced them to change however, growing over the centuries. They sport horns that can grow up to nine points on each of them, which are used primarily in mating rituals. When threatened they will turn their horns on attackers. Their diet revolves mainly around grass, but are not above scavenging squirrel carcasses when times are tough.
When starving or rutting, the Siika will attempt to charge and gouge their opponents, or kick at them with either set of legs. Rabid Siika have been observed to bite at creatures, but it has not been seen in healthy individuals.
The Siika have powerful rear legs that can propel them faster than your average villager. when they are overtaken or trapped, they turn their sharp horns on their attackers, as well as their hooves. They travel in large groups as a form of protection from predators, as when one is attacked the others rush to their defense.
The gestation period for Siika is ~3 to ~6 months, with mothers able to birth six fawns at a time. Rutting season commonly lasts from September to January, with most Siika being born in the spring. They reach sexual age at two years, and can breed for the rest of their lives, ensuring there is never a low-population. Females secrete a musk from their skin when in heat, which attracts males, but also some predators.
Siika feed primarily on grass, bushes, leaves and other such vegetation, but have been observed eating small rodents if starving. They are fond of fruit and will commonly feed on that when possible, being frequent sights at orchards.