Thanks to the Freecycler who provided this yellow sweatshirt (and the blue one that became a peacock)!
How to make this cool pineapple costume: obtain a large yellow sweatshirt, adult size preferred. With a good brown crayon, mark diagonal lines. (Paint doesn't come out as neat as crayon.) As you may already be aware, crayon does not come out in the wash.
Obtain some fancy green paper (we bought a big shiny gift bag for a dollar). Mark and cut a crown of long tapered leaves. Keep in mind that the height of the crown will make it tippy. Attach a long ribbon (or two) (or elastic) (or figure out something else that works) and wear with pride!