Final answer:
The Fairy Godmother uses a magical incantation in Cinderella.
Step-by-step explanation:
The subject of this question is English and it pertains to the study of fairy tales or fantastical stories. The phrase 'Bibbidi-bobbidi-you know it!' is an example of a magical incantation used by the Fairy Godmother in the story of Cinderella. It is a part of the fairy tale narrative where the Fairy Godmother uses her magical powers to transform Cinderella.