The tooth fairy is a popular American legend for children. When a child looses atooth he places it under his pillow while he sleeps and, according to tradition, thischaracter will change it for a gift. This tradition is almost universal, but takesdifferent forms in different cultures. He is known as "Ratoncito Pérez" in Spanishspeaking countries. His introduction to Child mythology is a story from theimagination of the Jesuit Luis Coloma. In 1894, the father asked Coloma to writea story when Alfonso XIII, who was then 8 years, lost a tooth.