In traditional festive legend and popular culture, Santa Claus's reindeer are said to pull a sleigh through the night sky to help Santa Claus deliver gifts to children on Christmas Eve. The number of reindeer characters, and the names given to them (if any) vary in different versions, but those frequently cited in the United States and Canada are the eight listed in Clement Clarke Moore's 1823 poem A Visit from St. Nicholas, the work that is largely responsible for the reindeer becoming popularly known. In the original poem, the names of the reindeer are given as Dasher, Dancer, Prancer, Vixen, Comet, Cupid, Dunder and Blixem.The popularity of Robert L. May's 1939 storybook Rudolph the Red-Nosed Reindeer, and Gene Autry's 1949 Christmas song "Rudolph the Red-Nosed Reindeer", resulted in Rudolph often being included as the ninth character. Many other variations in reindeer names and number have appeared in fiction, music, film and TV. Source: Wikipedia (en)