Feet of clay

Feet of clay is an expression now commonly used to refer to a weakness or character flaw, especially in people of prominence.
Origin and meaning.
The phrase derives from the interpretation of the dream of Nebuchadnezzar, King of Babylon, by the prophet Daniel as recounted in the Book of Daniel:
Notable uses.
A well known instance of this phrase is in Byron's poem, "Ode to Napoleon Buonaparte":
<poem>
Thanks for that lesson—it will teach 
 To after-warriors more 
Than high Philosophy can preach, 
 And vainly preach’d before. 
That spell upon the minds of men 
Breaks never to unite again, 
 That led them to adore 
Those Pagod things of sabre sway, 
With fronts of brass, and feet of clay.</poem>
In the Abba song Happy New Year, written by Björn Ulvaeus and Benny Andersson, man is said to have feet of clay:
<poem>
Oh yes, man is a fool
And he thinks he'll be okay
Dragging on, feet of clay
Never knowing he's astray
Keeps on going anyway 
</poem>