The Orphan Egg (1953)

As usual, little Dinky Duck gets no cooperation as he goes about his usual rounds doing good deeds. He finds an orphan egg, and, unable to get anyone else to care for it, he takes it home with him. After it hatches, he feeds the young bird as it grows ever larger. Meanhile, back in the barnyard, a sneaky fox has captured all the farm animals and birds including, to the fox's delight, the succulent ducks and chewy chickens. But Dinky's bird, now a full-size eagle, comes to the rescue and, as a result, Dinky is acclaimed a hero.