One of my twins wanted to go as Mad-Eye Moody this year. He's a big Harry Potter fan.
And, his costume was pretty easy. No sewing involved this time. He wore a brown t-shirt, khakis, and an old "pleather" jacket of mine. He carried a wand that was really the staff of one of those little American flags everyone waves on the 4th of July.
The main construction part on his costume was the "mad" eye. Years back, we bought a box of plastic animals from Michael's or somewhere. Its lid was a spinning globe. I held onto it, thinking it might come in handy sometime. And it totally did! I painted the globe to look like an eye. I hot glued it to some black felt, and attached a ribbon. Easy (and free, since I already had all the supplies!) mad-eye.