What is "hircocervus"

The hircocervus (, "billy goat" + cervus, "stag") or tragelaph (, "billy goat" + έλαφος, elaphos, "stag"), also known as a goat-stag or horse-stag, was a legendary creature imagined to be half- goat, half- stag.

The creature is now best-known through The Trusty Servant painting in Winchester College, representing the ideal virtues of its alumni.