crna ovca

1. black sheep
   On je oduvek bio crna ovca naše porodice. — He's always been the black sheep of our family.
   U svakom kolektivu ima neka crna ovca. — Every team has its black sheep.

«Паршивая овца» fits when actual misconduct is meant. Compare bela vrana: crna ovca stresses the group's disapproval, while bela vrana stresses merely being different.