An allusion to an egg that has gone bad or turned rotten.
bad egg (plural bad eggs)
- (Britain, idiomatic) Someone whose behaviour is reprehensible or irresponsible; a rogue.
- 1906, Horatio Alger, Joe the Hotel Boy,
- "Dat's right!" piped up the newsboy who had brought the policeman. "I see him do de trick jest a minit ago!"
- "This is a plot against me!" fumed the swindler.
- "Dat feller is a bad egg!" went on the newsboy. "His name is Bill Butts. He's a slick one, he is. Hits de country jays strong, he does!"
- ^ “A bad egg” in Gary Martin, The Phrase Finder, 1997–, retrieved 28 December 2017; “egg” in Douglas Harper, Online Etymology Dictionary, 2001–2018, retrieved 28 December 2017.