羊质虎皮

羊质虎皮 [yáng zhì hǔ pí]

1. ■ a sheep in a tiger's skin -- outwardly strong, inwardly weak; an ass in a lion's skin -- a dressed-up weakling; a monkey in a lion's hide; appear to be tough outwardly, be timid inwardly; be fierce in appearance but weak within [in essence]; be fierce of visage but faint of heart