Horton Hatches the Egg (1942)

Horton the elephant agrees to watch over lazy Maisie bird's egg while she vacations. Much later, after standing (and sitting) guard 100-percent faith-fully through rain and snow, Horton and the egg are captured by three hunters and put in a circus. Coincidentally, Maisie happen to fly by just as the egg is about to hatch and demands that Horton give it back to her.