My kid sister (of Macbeth fame) is certainly following in the footsteps of her older brother. Here are some choice quotes demonstrating her progress:

• "I'm TOTALLY EVIL!" -- Age 7

• (Repeatedly whispered over the sleeping body of her 17-year-old sister):
  "You're not who you are. You just think you are." -- Age 8

• "Aw -- a pirate ate my pie!" -- Age 9

• "Evil, evil, evil, AARRGGHH!!" (Begins panting like a dog) -- Age 9

• Her: "Must eat human flesh! You know, I've had my eye on that chest of yours for quite some time...."
  Me: "Wow, really, I'm flattered, but I think you should just have some pizza instead."
  Her: "Aw, but that doesn't contain human blood!" -- Age 9

• (Dancing erratically):
  "Gotta shake my bum-skin! Gotta shake my everything-skin!" -- Age 9

• (Upon seeing the reputation of this writeup):
  "I gotta keep saying the darndest things!" -- Age 9

• (Singing):
  "If everyone were a bit more drooly,
  The world would be a better place!
  Now let's do the Charleston!" -- Age 9

Fear not; I shall add more to this writeup as circumstances develop. Now you too shall know the warning signs of a potential insaniac in your midst.