We've covered alternatives to the cheap, plastic costumes that line the shelves this time of year. You know all about going vintage, handmade, and hand-me-down to reduce your Halloween waste. But when October 30 rolls around and plans for an elaborate costume based on your favorite literary character have fallen through, your options may seem limited: a bed sheet ghost or a quick trip to the nearest grocery store for a "Sexy [Whatever they have left]" costume? Put down the plastic, and make one of these easy, eco-inspired costumes that let you send a message (and still get the respectful "ah, you are very smart" head nod that your Holden Caulfield costume would've prompted) without too much effort or waste. 

Energy Vampire: Remind your fellow partygoers about the waste of standby power from unused but plugged in appliances. A large box can easily be turned into a computer with fangs, or a suit and black bed-sheet cape can be decorated with large paper power outlets to show the terrifying danger of wasting energy. 

Endangered Species: Spread the word about your favorite furry (or scaly, slimy, or feathered) friends who face extinction. A grey tracksuit with a paper-cone horn and ears becomes a message of solidarity for endangered rhinos, and animal costumes are cute on everyone. Search the endangered species list for your favorite animal, or search online for detailed DIYs, like this caribou costume tutorial from YouTube user BouTheCaribou.

Mother Earth: There are a lot of Mother Earth costume interpretations out there, so go with what feels right (or whatever is handy). Forgot to rake the yard? Glue a bunch of leaves to a dress and wear green tights. A great Mother Nature costume can also rely largely on pretty, ethereal makeup. It's quick, easy, and spreads the word for a good cause, so if your friends try to guilt trip you about not putting effort into your costume, you can give it right back with a lecture about their unnecessary SUV.

Global Warming: Grab a fan or a spray bottle and a blue shirt, add green construction paper continents, and voila! You have a terrifyingly serious threat to our health and safety. Go scare Al Gore.

FrankenFood: Are your friends appropriately frightened about GMOs on their dinner tables? Scare them with monster fruit! A homemade fruit costume easily turns into its creepy counterpart with the addition of some zombie makeup and a few large bolts to the neck. 

Now that you have your costume, go forth and frighten (and educate!). But don't be get preachy. Nothing ruins Halloween like a preachy genetically modified apple.