*Brebis qui bêle perd sa goulée = It is the silent sow that sucks the wash.
La brebis galeuse = The black sheep.
Il ne faut qu’une brebis galeuse pour infecter tout le troupeau = One scabby sheep will taint the whole flock; One ill weed mars a whole pot of pottage.
[Also: Pomme pourrie gâte sa compagnie = One rotten apple spoils the whole basket.]
Bredouille
Revenir bredouille = (of sportsmen) To return with an empty bag; To have made an unsuccessful attempt; To return disappointed.
Se coucher bredouille = To go to bed supperless.
*À cheval donné on ne regarde pas à la bride = One does not look a gift-horse in the mouth.