It was actually just a joke.
The Swan was an exception.
The renowned ballerina, Anna Pavlova, supposedly performance The Swan 4000 times.
Originally, there were 14 movements.
The original pieces are:
Introduction et marche royale du lion (Introduction and Royal March of the Lion)
Poules et coqs (Hens and Roosters)
Hémiones - animaux véloces (Wild Asses - quick animals)
L'éléphant (The Elephant)
Personnages à longues oreilles (Characters with Long Ears)
Le coucou au fond des bois (The Cuckoo in the Depths of the Woods)
Le cygne (The Swan)