Using the PAR code to play as Shang Tsung, I came across this little trick by accident:

Morphing!

(Note: Code is listed in the link)

Seems that if you hold Forward/Down diagonally and BLK, then let the opponent hit you, the morph will trigger itself on its own. You'll randomly morph into any of the seven original fighters. I have yet to morph into Goro.

I haven't any idea if this is well-known around here or not, since I don't exactly frequent here much anymore, but hey, if it isn't, new trick for you I suppose.