bad apple

Etymology
From the proverb “one bad apple can spoil the whole bunch” (or a variant thereof).

Noun

 * 1)  A person who is not wholesome, honest, or trustworthy, especially one who has an adverse influence on others.

Translations

 * Chinese:
 * Mandarin:, 老鼠屎
 * Dutch: rotte appel
 * Finnish:
 * French:
 * German:, , fauler Apfel, faules Ei
 * Hindi: गंदी मछली
 * Italian: mela marcia
 * Japanese:
 * Polish:
 * Portuguese:
 * Romanian: poamă rea
 * Russian: парши́вая овца́
 * Scottish Gaelic: droch-isean
 * Slovak: čierna ovca
 * Spanish: manzana podrida, mal elemento, ,
 * Swedish: ruttet ägg,