Do the Monster Slapdash
Hide it underneath yourself to go as, "The Guy That Was So Thirsty That He Was Forced To Drink His Own Butt."
Kludge (klooj, n.): a clumsy, inelegant, improvised solution to an engineering problem. Kludge-O-Ween (klooj-oh-ween, n.): a makeshift, half-assed solution to Halloween. When it's too late to worry about finding the perfect costume, it's time to realize that ANYTHING can be a costume.