Slideshow will continue in seconds. Click to skip
Forget to plan a costume this year? Click through for six great last-minute ideas that'll make it look like you didn't.
Harold and His Purple Crayon
In Your Closet Already: Blue sweatpants and a long-sleeved shirt (and don't worry too much about what shade of blue it is, Harold's outfit has ranged from sky to turquoise over time).
Borrow or Buy: The purple crayon, of course!

If You Have Time: Matching blue sneakers are a nice touch.
Where's Waldo
In Your Closet Already: Red striped shirt, jeans and brown shoes.
Borrow or Buy: A red and white ski cap and round-frame glasses.

If You Have Time: Find some trademark Waldo accessories, like a camera or cane, to carry.
French Kiss
In Your Closet Already: A striped shirt, neck scarf and beret.
Borrow or Buy:
Face paint.

If You Have Time: This is even funnier if you have a black wig or guitar prop.
Bill Cunningham
In Your Closet Already: Almost everything: a white button-down, khakis, practical shoes, a blue anorak and—of course—a camera.
Borrow or Buy: An red men's tie.

If You Have Time: Ride to the party on a vintage-inspired bicycle.
A Formal Apology
In Your Closet Already: An sort of fancy dress or suit.
Borrow or Buy: String and paperboard to make a big "I'm sorry" sign for your neck.

If You Have Time: Order a corsage for your outfit.
Emoji Girl
In Your Closet Already: A pink V-neck sweater.
Borrow or Buy: A brown-haired wig if you aren't a brunette.

If You Have Time: Study your smart phone and practice her exact gestures in the mirror.