Jigglypuff looks like a pink pillow with oversized creepy eyes.  Take away the looks and you get a deceptive attacker.  He's agile, but not fast and has some awfully strange attacks.  For all of you that want to slap him when he "falls asleep," (down, B) that is really a very close range attack.  It does good damage but work with it before you try doing this move against advanced players.  Like me, he also sings to lull his attackers to sleep.  Hint: when they are asleep use the down B attack against him.