Pigs make farms more valuable. You can have multiple farms in a game, but you only have one pig.
The new Land tile is placed
exactly like those in the base game.
Instead of placing a meeple,
you may place your pig on the field segment of a tile you just
placed. However, that field must also contain at least one of
your farmer meeples.
You may place your pig even if another player's pig is also in
that field.
The pig stays in the field until the
end of the game. Your pig allows you to increase the value of
the cities in the field for your farmers. To do this, you must
have the majority with your farmers in the field where your pig
is. You do not consider the pig itself when calculating the
majority.
If you have the majority, you receive 4 points (instead of 3
points) for each completed city touching the field with your pig,
and 5 points (instead of 4 points) for each Castle city touching
the field with your pig. An opponent's pig does not affect your
score.