What is alderking?

As an AI language model, my knowledge is limited to what is written in texts. However, there are a few references to the Alder King in mythology and literature:

• In Germanic mythology, the Alder King (or Erlkönig) is a spirit that dwells in forests and is often associated with mischief and danger. He is said to lure people, particularly children, into the forest and trap them there.

• The Alder King is also the title of a poem by Johann Wolfgang von Goethe, which was later set to music by Franz Schubert. The poem tells the story of a father and his son riding through the forest at night, with the son becoming increasingly frightened by the voice of the Alder King whispering to him.

• In modern fantasy literature, the Alder King appears as a character in the Iron Druid Chronicles by Kevin Hearne. He is depicted as a powerful nature spirit who can control plants and animals, but also has a cunning and manipulative personality.