работать как папа Карло

Etymology
lit. 'to work like papa Carlo'. The expression originated after the character of hardworking woodcarver Carlo in the popular children’s motion picture "Приключе́ния Бурати́но" (The Adventures of Buratino), 1975, based on the novel "The Little Gold Key or the Adventures of Buratino" by Aleksey Tolstoy, which, in turn, is an adaptation of "The Adventures of Pinocchio" by Carlo Collodi.

Verb

 * 1)  to work hard, to work like a dog