a wolf in sheep's clothing
... a suit (of clothes) 套服 a wolf in sheep's clothing 绵里藏针; 绵里藏针 an ancient type of clothing 裎 ...
绵里藏针,汉语成语,拼音是mián lǐ cáng zhēn,意思是棉絮里面藏着针,形容柔中有刚;也比喻外貌和善,内心刻毒。出自《曲江柳》。