So this is how species work in my anthro ungulate AU. It’s roughly based off of BNA where, if both parents are different species, the child only inherits one species, it does not become a hybrid species. There are a few exceptions though. For example, if a deer dad and cow mom have a baby, the baby will be either a deer or a cow. It will not be a hybrid, though it *can* inherit either parents’ fur color and patterns (it can be a deer with cow spots but anatomically it is a deer with no cow anatomy, therefore, not considered a hybrid). Now if the parents are of similar species, such as a dad horse and a mom zebra, the baby will be a zorse, since this is a real hybrid in the real world between those species. Now for the uncommon exception (in the case of Dio and Reyna’s offspring). Once one turns vampiric, they no longer follow the laws of nature. As such, any vampires at conception are not bound to the laws of inheriting one species. Therefore, Reyna (elk) and Dio (hartebeest) will not produce either elk or hartebeest offspring but they will be hybrids (hartelks as I like to call them :3) and randomly inherit traits from the parents, so that siblings could vary a lot in appearance. This same logic applies to any immortal creature in the universe. However, both parents have to be immortal for the child to not be bound by the laws of speciesism. In the case of Shiobana and Dio/Jonathan, the offspring will still be bound by mortal laws and inherit one species even if one other parent is immortal.