"Pig" can mean three things when describing a person. It can describe someone who is dirty or unhygienic, it can describe someone who eats a lot of food, particularly if they eat messily, or it can describe a man who hits on women when it isn't appropriate, particularly if he is lewd.

Generally calling someone a 'pig' means they are some combination of: fat, lazy, eat too much, eat messily, loud and/or dirty.

You can also say "Look at your (bed)room, you live like a pig" or "Your room's a pigsty". https://en.oxforddictionaries.com/definition/pigsty

Lol

All of which are very unfair to the pink creature with the curled tail.