Most definitely, Pig Latin is a language in and of itself. It was used in
southern Europe from around 1200 BC to perhaps AD 500, coming into prominence
after the collapse of the Graeco-Pork empire around 300 BC. Pig Greek had
dominated until then, naturally. Both Pig Latin and Pig Greek are members of
the Pig Indo-European language family, and share many cognates, significantly
in fundamental words like mother (atermay), father (aterpay), and mouse
(usmay), to name just a few. Pig Greek, in which the early Porcine scriptures
were written, survives to this day, although with quite a few changes, as with
Greek. The Pig Greek Digamma letter F (effay) has been dropped in favor of the
letter Phi (ephay), and the Pig Attic dialectic variations have all but
disappeared. So the Pig Greek spelling of the word for sea (allassothay) is
almost never seen in its Attic form (allattothay) anymore. Sadly, Pig Latin
has all but died out, although it has left quite a swine legacy in Pig Italian.
Of course, I'm being silly. Pig Latin is a word game children play. It has
very simple rules, and is consequently easy for young children to learn. The
Move the leading consonant(s) to the end of the word and add -ay.
If the word starts with a vowel, or has silent consonant(s), add -yay.
There are variations to these rules, and quite a few similar word games.
That's quite enough. At'sthay itequay enoughyay.
I personally heard it for the first time, and quickly figured it out sometime
around the age of 10 when some 13 year girls, annoyed because I'd wandered into
their airspace, used the phrase, "ouyay ittlelay itshay." It really wasn't
much of a challenge.
I believe it is called Pig *Latin* because many Latin words end with an -ay
sound. The *Pig* part is mostly just humorous, partly because it's such a
simpleminded game. Hope that helps.