A pig is a pinkish domesticated quadraped of the genus sus that goes 'oink'. It is commonly farmed for bacon, ham, and pork. Wild pigs (boars) also existed in Europe.
Some period cultures had a taboo against eating meat from pigs. This is because of the virus and bacteria that pigs can carry.
For complex reasons relating to the tendency for food at events to be limited in volume, making a "pig" a monarch is generally frowned on, since they then expect to get rapid access to the front of the feast queue. In some cases, their conversation can also be quite 'boring'.