High Quality Content by WIKIPEDIA articles! The Simpsons Treehouse of Horror episodes, also known as The Simpsons Halloween episodes, are a series of episodes in the animated series The Simpsons. They are Halloween specials, each consisting of three separate, self-contained segments. These segments usually involve the Simpson family in some horror, science fiction, or supernatural setting. They take place outside the show`s normal continuity and completely abandon any pretense of being realistic. The first, entitled "Treehouse of Horror", aired on October 25, 1990, as part of the second season and was inspired by EC Comics horror tales. The episodes are known for being far more violent and much darker than an average Simpsons episode. As of 2011, there are 22 Treehouse of Horror episodes, with one airing every year, and the newest episode, "Treehouse of Horror XXII", premiered on October 30, 2011.