Elves are depicted throughout Germanic folklore as beautiful, majestic beings who wield powerful, and often devastating, supernatural powers.  They're said to live beneath mounds and hills, and leave their homes mainly to hold enchanted celebrations or go hunting on moonlit nights.  Elvish music is able to entrance a man to dance indefinitely, and if angered they might afflict their victim with "elf-shot," which can cause blindness or worse.  Elves are often depicted in popular fiction, but the faithfulness to their folkloric roots varies considerably from the fairly faithful representations of Tolkien to the silliness of Santa's helpers.  The folk traditions of the elves continue today, however, and witnesses still sometimes report encounters with the Fair Folk.