Hircocervus

The hircocervus (Latin: hircus, "billy goat" + cervus, "stag") or tragelaph (Greek: τράγος, romanized: tragos, "billy goat" + έλαφος, elaphos, "stag"), also known as a goat-stag, was a legendary creature imagined to be half-goat, half-stag.

Origins

In Plato's Republic, Socrates speaks of his own image-making as similar to that of painters who paint goat-stags, combining the features of different things together (488a).

In his work De Interpretatione, Aristotle utilized the idea of a fabulous goat-stag to express the philosophical concept of something that is describable even though it does not really exist. His Greek "τραγέλαφος" was rendered into Latin "hircocervus" by Boethius.

Aristotle returned to this in the Posterior Analytics to argue that, though the word is definable, there can be no definition of the species as it has no members. He also uses the tragelaphos together with the Sphinx in the Physics to illustrate the point that a non-existent creature has no spatial location. On the other hand, Diodorus Siculus treats the tragelaphos as an existing animal, and there are references in Greek literature to other hybrid creatures such as the hippelaphos (horse-stag).

The word hircocervus first appears in the English language in a medieval manuscript dating from 1398 (now at the Bodleian Library).

In culture

Rabbinic literature refers to an animal called a koy which is halfway between domesticated and wild species of quadruped, and debates how far it is subject to the laws governing each category. Scholars are divided on whether the rabbis believed the koy to be a real creature or an imaginary example used for a hypothetical discussion.