Pig emoji represents the domestic animal, which is grown for meat. The wild version of basically the same animal is depicted by Boar emoji. The pigs in general are unfairly associated with dirt, extremely impolite behavior, and bad manners - so no wonder that along with its direct meaning this emoji is also used as an insult or just a characteristic of a person to which the same unpleasant traits and habits are attributed.
🐖 Pig emoji
refers to the animals and nature