The Flying Spaghetti Monster (or FSM) is the deity of the parody religion the Church of the Flying Spaghetti Monster or Pastafarianism. It was created in 2005 by Bobby Henderson as a satirical protest to the decision by the Kansas State Board of Education to require the teaching of intelligent design as an alternative to biological evolution in public schools. Since the intelligent design movement used ambiguous references to an unspecified "Intelligent Designer" to avoid court rulings prohibiting the teaching of creationism as a science, this presumably left open the possibility that any imaginable thing could fill that role.
In an open letter sent to the education board, Henderson parodies the concept of intelligent design by professing belief in a supernatural creator, which closely resembles spaghetti and meatballs. He furthermore calls for the "Pastafarian" (a play on Rastafarian) theory of creation to be taught in science classrooms.
Due to its recent popularity and media exposure, the Flying Spaghetti Monster is often used by atheists, agnostics (known by Pastafarians as "spagnostics"), and others as a modern version of Russell's teapot and the Invisible Pink Unicorn.