Plan a fearsomely fun Halloween costume with this Adult Wolf Mask from Hyde and EEK! Boutique?. The multicolored polypropylene mask is shaped like a wolf's head and glows under blacklight for an eerie effect. It fits a maximum head size of 23 inches and secures in back to help keep you in character. Hyde and EEK! Boutique?: Thrilling delights. Curious oddities.