The Brothers Grimm 
The Seven Ravens 

In The Seven Ravens a peasant sends his seven sons to fetch water for his daughter’s christening. Having lost their pails in the well, they are afraid to return home without having completed their task. The peasant, thinking they have gone off to play, curses them whereupon they are immediately transformed into ravens. When the daughter is grown up she sets off to discover the whereabouts of her long-lost brothers. This folk tale exists in multiple varieties and was adapted into film in 1937.