In the evening of his life, the donkey Cadichon remembers his past adventures. His very first memory is how he was found by ruthless farmers and how he bonded with a dog. When the dog disappears overnight, Cadichon decides he has to flee.
Having escaped the ruthless farmers, Cadichon is being found by a friendly family and sold to noble children that use him as mount. During a tour, a boy falls into a river - and is heroically rescued by Cadichon.
Cadichon winds up with unethical owners yet again but is soon bought back into the wealthy family and returns to their manor. Although he rescues Caroline from certain doom during a fire, he is abandoned and sent into the woods.
Cadichon befriends an owl and a boar. He is then attracted to the carnival in Sain-Mamet where he is incorporated into a coach race. He then meets Jacques, a boy living with his rich grandmother, and is invited to their manor in Dijon.
Jacques saves Cadichon from food poisoning. On a ride out, they encounter a presumably haunted castle. When Cadichon travels there alone in secret, he encounters a band of smugglers, so he makes sure to lure the gendarmerie to the ruins.
At the countess' manor, Cadichon is in for a surprise when he gets a visit by an old friend. He is then tasked with an important mission by the gendarmerie and saves a gendarme's life when he falls from a cliff.
Hilarity ensues when a photographer arrives at the manor to take a family portrait and Cadichon is not invited the the shoot by the photographer. Later, Cadichon's life hangs by a literal thread when he accidentally joins a balloon ride.
Cadichon is sold to an old man and forced into hard labor at a windmill. Although his days are long and hard, he gives his best and quickly makes new friends. After leaving the mill, he helps out some townspeople before pushing along.
After stopping a bunch of cabbage thieves, Cadichon is pardoned by the rich family and reinstated into the possession of the family. On a picnic trip to the ruins, Cadichon has to fight a bear - and is able to make amends with Antoine.
Word of Cadichon's good deeds quickly spreads, but the burglars return and hold him hostage. Cadichon's old friends reunite to rescue him. Jacques presents Cadichon with a photo album - which is, unbeknownst to Cadichon - a parting gift.