Flossie was a deer who lived in the Forest of Burzee.
One winter Flossie and another deer, Glossie, visited their friend Claus in the Laughing Valley. He was as good as imprisoned in the Valley by the snow, but he was impressed that the deer could walk upon its frozen surface. During their visit a suggestion was made that Claus could travel faster and farther if the deer would pull him and his toys on a sled.
Flossie and Glossie were intelligent creatures and curious about the outside world, so they asked Will Knook for his permission to help Claus. The Knook agreed only if they returned to the forest by dawn. On their first journey, Flossie and Glossie drew Claus to a village and a city, but returned just as the sun was rising.
Will was upset at their tardiness and planned to unleash the stinging gnats on them, but the Great Ak interceded on their behalf. The Prince of the Knooks of Burzee established Flossie and Glossie as the first reindeer, set aside to help Claus one night a year. (The Life and Adventures of Santa Claus)