a needle hidden in silk floss— a ruthless character behind a gentle appearance; an iron hand in a velvet glove
? 此人老奸巨猾，～。This man was a crafty old scoundrel and had a ruthless character behind a gentle appearance.
綿里藏針
needle hidden in silk floss—gentle but firm; tough despite superficial softness;iron hand in a velvet glove
綿里藏針mián lǐ cánɡ zhēn
棉絮里藏著針。比喻柔中有剛。an iron hand in a velvet glove, a ruthless character behind a gentle appearance