Halloween derives from an ancient Celtic ritual, Samhain. This ritual included dressing up in costumes and wearing masks to hide from or blend in with the ghosts believed to walk the earth on this night. Today, Halloween is still celebrated by dressing up in costume. Nowadays, however, costumes are meant to amuse and delight other people rather than appease or confuse the dead. You can create some clever "twosome" costumes and go as a Halloween matched set.
A Matched Set
There are a number of things that naturally come "paired up" and could be re-created as a duo Halloween costume. Go as salt and pepper shakers, cream and sugar, mustard and ketchup, bacon and eggs or peanut butter and jelly. For a more modern twist, how about dressing as a computer and mouse or cell phone and "texting finger?" For a more allegorical approach, consider dressing as "the birds and the bees," a fly and honey, "birds of a feather flocking together" or someone "crying" and "spilt milk."
Celebrity couples, couples from TV, movies or books and famous sets of twins all provide options for a duo Halloween costume idea. Dress as famous cartoon and comic characters Mickey and Minnie Mouse, Bugs Bunny and Elmer Fudd, Superman and Superwoman or Batman and Robin. Famous couples include Adam and Eve, Sonny and Cher, Bill and Hillary Clinton (or Bill and Monica Lewinski), Mr. and Mrs. Potato Head and Barbie and Ken. Twin costumes to consider include: Mary Kate and Ashley, Tweedledum and Tweedledee from "Alice in Wonderland" and Thing One and Thing Two from "The Cat in the Hat."
Choose a pair that is noted for their "oppositeness." Dress as a cowboy and an Indian, a Yankees and a Red Sox fan or angel and a devil. Go for story characters Glenda the Good Witch and the Wicked Witch of the West from "The Wizard of Oz" or the Big Bad Wolf and Little Red Riding Hood. Other opposite costume ideas include dressing as winter and summer, oil and water, a PC and a Mac computer or Coke and Pepsi. For a more abstract costume idea, create your own interpretation of some classically opposite concepts like truth and fiction, love and hate or happiness and sadness.
If you don't mind being stuck like glue to your costume partner, consider dressing as two peas in a pod, a kangaroo and its baby joey, two interlocking Legos, a plug and socket, a hot dog and bun or a prisoner and his ball and chain. If one person doesn't mind being the tail end of the costume, you could go as a two-person horse or car. For these costume ideas, you'll need to create a costume that allows one persons to be the front and one person the rear, with each person's legs becoming the horse's legs or the car's wheels.