King Snout was a king and was also an actual pig.
King Snout was crowned by the people because Prince Percival told the citizens that they should crown a pig instead of him so "that they could be ruled by their own kind". The citizens took Prince Percival's word and so crowned a pig, later named King Snout.
King Snout reigned over the people for six happy and peaceful years. This is part of the adventure update that includes map pieces and rewards of a statue that gives public order.