October is a busy month for mask maker Eric Bornstein, but you won't find him churning out rubbery costumes for trick-or-treaters. Bornstein makes one-of-a-kind creations in his awesomely anarchic studio, Behind the Mask. And he's just as colorful as his custom-made characters. Widely traveled and extremely well read, he's a fast-talking tornado of energy, riffing on ancient Eastern theater one moment and old Hollywood monster movies the next. We stopped by his Somerville living room for a tour and a tête-à-tête.