have feet of clay

US /hæv fiːt əv kleɪ/
UK /hæv fiːt əv kleɪ/
"have feet of clay" picture
1.

to have a hidden flaw or weakness in one's character, despite outward appearances of strength or integrity

:
The public was shocked to learn that their revered leader, who seemed so perfect, actually had feet of clay.
Despite his impressive resume, it became clear that the new manager had feet of clay when he failed to handle the first major crisis.