Last minute DIY Halloween costumes

Wilson, from Home Improvement.

Grab a fisherman's hat and some Popsicle sticks and you're good to go.

50 shades of gray

Tape a large amount of gray shaded pallets to yourself.

Cactus

Green sweatshirt and sweatpants, cut up straws for the needles or use whatever you see fit.

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Easy way to not wear a costume while technically wearing a costume. Just draw/paint on a t-shirt

Quailman

get some red tape for the Q (or whatever you think would be easiest), wear that underwear on the outside, put a belt on your head, add a red cape.

Lego peice

Get a cardboard box, some paint, and cheap plastic containers from the dollar store.

Cat scratch post

Buy a large cat scratching post, and wear that shit. Cut a hole for your head if necessary.

Stick man

All white clothes and a paper plate with electrical tape on it

Identity theif

A bunch of name tags

Any App

Be creative with this one. Grab some cardboard and print out whatever logo you want, or set it up like a facebook profile/instagram picture/whatever your favorite app is.