Did you know...
That a demon lurks in this town? They say that sometimes, when you fall asleep at night, you can see him hiding in your dreams. He's the one on the edge of your vision, watching, waiting. Lurking. There.
Some folks say that he's blue- the color of the ocean in a cold night. Some folks insist that he's yellow- as radiant as the sun when it's beating down on you. And then I've met people who say that he had introduced himself as simply Bill Cipher. But others claimed that his full name was William Mischief Cipher.

There are folks in this town who believe that they're two separate entities. Similar in powers and abilities, but nearly opposites in mannerisms and personality. One always laughing at what you do; One always scoffing at what you do.

No, but they're wrong-
I've met them both, you see. And they're definitely not separate beings. But neither are they the same...
Because they share a body,
but differ in mind....
Two sides of the same coin.