Micro Fiction is very short prose fiction. Smaller than Flash Fiction but bigger than a haiku. Usually 500 words or less. There are some famous short short stories, including Hemingway’s - For Sale: baby shoes, never worn.
Lovecraftian fiction usually takes the form of Cosmic Horror, Weird Fiction, or Speculative or Science Fiction with a Horror twist, as well as horror or ghost stories with an uncanny tone.
