Queen's College, Oxford, celebrates the tradition of the Boar's Head Feast whereby three chefs bring a boar's head into hall, with a procession of a solo singer who sings the first verse, accompanied by torch bearers and followed by a choir. The procession stops during verses and walks during the chorus. The head is placed on the high table, and the Provost distributes the herbs to the choir and the orange from the Boar's mouth to the solo singer.
William Henry Husk, Librarian to the Sacred Harmonic Society, wrote about the tradition in 1868 in his Songs of the Nativity Being Christmas Carols, Ancient and Modern:
Where an amusing tradition formerly current in Oxford concerning the boar's head custom, which represented that usage as a commemoration of an act of valour performed by a student of the college, who, while walking in the neighbouring forest of Shotover and reading Aristotle, was suddenly attacked by a wild boar. The furious beast came open-mouthed upon the youth, who, however, very courageously, and with a happy presence of mind, thrust the volume he was reading down the boar's throat, crying, "Græcum est," and fairly choked the savage with the sage. (Wikipedia)
You can listen to the carol at this link.