Бойся не той собаки, которая лает, а той, которая молчит
ONE DOESN'T NEED TO BE AFRAID OF A BARKING DOG, BUT HE SHOULD BE AFRAID OF A SILENT DOG
Англо-русский перевод ONE DOESN'T NEED TO BE AFRAID OF A BARKING DOG, BUT HE SHOULD BE AFRAID OF A SILENT DOG
English-Russian dictionary of English idioms. Англо-Русский словарь английских идиом. 2012