LordBrandon made his son a dinosaur costume out of mattress foam and spray paint. He said it cost him about $25 for materials, but a lot in labor. It was a labor of love.
I made a model in 3D, then used software to split it apart into a pattern, then I hung the foam on the wall and projected the pattern with a little pico projector, traced it with a sharpie, and cut it out with an electric turkey carving knife. It really seemed to come alive when I painted the eyes.
He'll be the best-dressed kid on the block for trick-or-treat, but all reddit could talk about was his socks.