The Erlkönig (Alder King), or Erlking, is a sinister, mythical elf who is said to linger in the woods. He goes around and kills children who stay in the woods too long, and kills them by a single touch. He is depicted in a number of German poems and ballads as a malevolent creature who haunts forests and carries off travelers to their deaths.
The name "Erlking" (German: Erlkönig, lit. "alder-king") is a name used in German Romanticism for the figure of a spirit or "king of the fairies." The name is an 18th-century mistranslation of the original Danish word elverkonge, "elf-king."
"An evil wood spirit appearing in Germany's Scharzwald. He charms people and leads them to their deaths. His name means "Alder King," and true to his name, he is the ruler of the alders of the forest. It is said that the Erlkonig is the strongest of the alder trees."