Fantastical animals are not literally patchwork hybrids

I have already said my piece about the illogical and inconsistent treatment of fictional animals in fantasy gaming and the lack of consistent criteria for determining what constitutes a beast or monstrosity. In this post, I will explain the place of real and fictional animals (or beasts in the D&D rules) within my cosmology.

Platypus and duckbunny, (c) nocturnalsea

Fictional animals are animals which do not exist in reality. This is a broad group which includes both speculative biology projects, mythical animals, and hybrid animals.

Hybrid animals are animals that are hybrids of two or more component animals. Many fictional animals in medieval bestiaries were described in terms of their resemblance to other animals, but they were not necessarily intended to be literal hybrids.

100% anatomically accurate unicorn

For example, the unicorn was described as having the head of a horse, the body of a stag, the beard of a goat, the tail of a lion and a spiral horn emerging from its forehead. This was not meant to imply it was a literal patchwork hybrid of those animals, but merely to give those who had not seen it first-hand a point of reference from which to visualize it.

By contrast, the gryphon was described as a physical and spiritual hybrid of the eagle and the lion. Like its component animals, it was the lord of the skies and the king of the beasts. However, it was described as a naturally occurring animal that bred true and shared no ancestry with lions and eagles; it displayed unique traits like an affinity for gold and laying eggs resembling agates.

gryphon anatomy, (c) pixiezilla

During the time in which these bestiaries were written, the naturalists believed that all animals which existed were created at the beginning of time and had remained unchanged since then. Contrary to what gaming books would have you believe, medieval naturalists were utterly ignorant of such things as ecology and evolution.

So the apparent hybrid animals that populate the pages of medieval bestiaries and game books alike are not really hybrids at all, but were only described as such by the naturalists who observed them.

That being said, vivimancers (magic-users that specialize in living creatures) have been known to experiment with fusing animals together. These test subjects would be true hybrids, but they would most likely be sterile due to the crudeness of their creation. If a liger or tigon is sterile even with the closeness between lions and tigers, then the same would probably hold true for creatures even further apart in nature.

Greek legendary monsters' family tree

An exception would be the creation of an exceptionally skilled vivimancer... such as a mother of monsters like the dragoness or the moon woman. Stories circulate of them giving birth to monsters combining aspects of other creatures and siring or bearing offspring of their own. However, these offspring are typically unique monsters themselves. For example, according to Greek mythology Chimera coupled with her brother Orthos and gave birth to the Sphinx and Nemean Lion. Both parents and children were unique, not self-sustaining races.