The Tooth Fairies and the Oath of Zooland

Tooth fairies do exist. Lindiway is a little girl who has never eaten candy. Due to that, her tooth, which has recently fallen, is of great value for the tooth fairies’ kingdom. However, her father has bad intentions to use that tooth and find it without breaking the rules, otherwise they will lose their magical skills. How will they do it? What is the Oath of Zooland?