The Red Balloon (Le Ballon rouge) begins with young Pascal walking to school alone in gritty inner-city Paris. he finds a large red balloon attached to the top of a lamp post and rescues it.
The balloon is then his companion. Everywhere the balloon goes, it causes Pascal trouble. It shortly becomes apparent that the balloon is sentient, and appreciates Pascal; it waits for him outside his apartment and reluctantly obeys his command.
The balloon is a metaphor for the whimsy of childhood. Regardless of any problems it may cause, the viewer always knows that Pascal is better off for having its company.
The Red Balloon won the oscar for best short film in 1959, and is a delight to see.