Mr. Hyde wasn't the only one with a Dr. Jekyll. Masters of the human psyche have suggested that we all have a shadow side, and what better time to explore it than during the spooky Scorpio holiday of transformation? This year the Moon will be in theatrical Leo, which favors exaggeration -- so the bigger the concept, and the further you take it, all the better!
Aries
The zodiac's warrior will have fun showing a softer side this year. A good fairy, a lovable puppy or an array of plush and cutesy costumes will make your Halloween as warm and sweet as s'mores.
Bonus boo: Ram costumes are only cool this year if you're wearing a football helmet ... but how about a different head-butting beast -- like a unicorn?
Taurus
Your sign rules the throat, so you'll be sensational as one of your favorite singers -- any era will do. From Bing Crosby to Beyonce, the fashion is as fun for you as the karaoke versions you'll sing to drive the point home.
Bonus boo: Don't you dare trick or treat without your adoring entourage!
Gemini
You're a candidate for costumes that tell a story or involve a joke -- think shark munching on a man, or the girl in King Kong's grip. Let your evil twin have a spin with a costume that represents the mischievous part of you.
Bonus boo: Got a date? Sew your clothes together and go as Siamese twins.
Cancer
Underneath your hard outer shell, you are soft and vulnerable, and maybe even a little bit wounded. That's why showing a little blood -- or a lot of gore -- will be fun for you. If you don't want to scare any kids, a vampire get-up with just a drop of blood from your mouth will be effective enough.
Bonus boo: You’re the sign of America, and would make a delightful Obama, Clinton or Palin!
Leo
You're sure to get applause when you go as a movie or television show character. If you can get a few friends to accompany you, even better -- because what would Pam be without a Jim, or Snooky without The Situation?
Bonus boo: Pull out the cat costume. You look so adorable in it that it never gets old!
Virgo
Finally, a chance to let your hair down -- or better yet, to wear a blonde wig. Tap into that campy side you never show the world by trying on Marilyn Monroe or Jessica Simpson; alternately, give the French maid or pirate vixen a spin.
Bonus boo: You'd also make a lovely Greek goddess!
Libra
Oh stylish one, it's time to make a statement. Personify your inner supermodel, or go as Tim Gunn, Heidi Klum or your favorite fashion icon. You'd also make a cheeky Gwen, Madonna or Carrie Bradshaw.
Bonus boo: If you're going out with someone, a clever couples costume will be a hit -- like a plug with a socket.
Scorpio
This is your year to go historic -- you'll be charming as a person from a bygone era. If you believe in reincarnation, embody one of your past lives. Whether you choose to be a cave dweller or Elizabethan-era princess, the details make the costume.
Bonus boo: Scorpio is also the sign of surgery, so consider going as a doctor or nurse!
Sagittarius
Dress as though you come from a different continent ... or better yet, a different planet! A Star Trek-er, Skywalker or character from Avatar will highlight your otherworldly qualities.
Bonus boo: Why not go as a knight on a horse to represent your equestrian kinship?
Capricorn
You know you secretly want to rule the world, and here's your shot at acting like you do. Go as royalty (Elvis, Michael or Prince Charles); a high-powered player (Oprah, Martha); or, a super hero (Wonder Woman).
Bonus boo: As the sign of climbing, you could also get some mileage as a mountain man -- or even a lumberjack.
Aquarius
It's your chance to get weird and wild. Whether you're Alice in Wonderland, Dorothy in Oz or a psychedelic mushroom in someone's trippy fantasy, you'll enjoy watching other people's reactions to whatever mood you set.
Bonus boo: Go as a hippie from Hair and sing about the dawning of your age.
Pisces
You've been accused so often of having mystical powers, you may as well personify the magical creature people think you are! Go as a witch, wizard, magician or fortune teller.
Bonus boo: A mermaid (or mer-dude, as the case may be) is the perfect expression of your fishy nature.