This comic took off when the author of Dilbert recommended it to his readers. Hence, some strips make references to Dilbert.
Side track a little, the phrase "pearls before swine" refers to the admonition "Neither cast ye your pearls before swine" that Jesus gave to Peter according to Matthew 7:6 in the Bible. According to Pastis, Rat, who considers himself a genius, casts his "pearls" of wisdom before Pig ("swine"), who is the only one naive enough to seriously listen.
Description of the two main characters: (Taken from wikipedia)
Rat is a megalomaniacal rat, and is an anti-hero. He is frequently critical of the strip's style and artwork as well as the other characters in the strip and many other living things. Often self-employed, most of his businesses involve either punishing or defrauding people for their ignorance, much in the same vein as Dogbert, though with a darker humor. Rat lives with Pig in a house somewhere in Albany, California.
Rat is an insensitive character in the strip, whose interactions with others are typically sarcastic, condescending, selfish, insulting and sometimes violent. Rat frequently breaks the fourth wall to berate his creator on his joke writing, artwork, or the general content of the strip itself.
However, Rat does have one weakness; women. Pigeta telling him that she is leaving for another character, (they are sometimes shown to be dating) his ego is crushed (in one strip, literally.) In another strip, Rat appears to have a nervous breakdown when trying to flirt with a female rat.
Pig is childlike and dim, but also well-meaning and kind, all of which leads to constant ridicule by his housemate Rat. Pig's jokes generally involve his incompetence and not knowing his true surroundings. Pig has a short-tempered girlfriend named Pigita. Pastis says that Pig is the easiest character to write for: "He just has to misunderstand everything that he hears, then when it's explained to him, he has to misunderstand that too."
Pig has a habit of talking to inanimate objects such as food, stop lights, bait, and various other things (although since in the "Pearls" universe the objects talk back, this is not as odd as it might otherwise be). His dimness is often exhibited in the strip. For instance, he once went to a Halloween party as a hostage and could not see, causing him to fail miserably at charades. Pig's least appropriate characteristic is his love of pork products; He likes bacon, ham, corn dogs, and so on, making him a cannibal, although he appears to misunderstand this. He is also sometimes able to tell which member of his family has been made into the food product.
Here are some comics of it I found from online. Take note that Pig eats BLT sandwiches which contain bacon. Haha.. Not trying to promote “cannibalism here”, mind you! Enjoy!