town briefly cuts to them in their space ship, watching the events and laughing maniacally at the Earthlings' suffering. The action then switches back to the actual story. The unofficial rule is that they must be in every episode, although quite often they will be forgotten and are added at the last moment, resulting in only a brief appearance. Their scene in "Treehouse of Horror VIII" nearly did not make the final cut of the episode, but David X. Cohen managed to persuade the producers to leave the scene in. Kang and Kodos were prominent characters in the 2015 episode "The Man Who Came to Be Dinner," which was not Halloween themed. Scary names Beginning with "Treehouse of Horror II", the producers decided to give the cast and crew of the show "scary names" in the opening and closing credits. Although the names quickly became more silly than scary, there have been a wide variety of special credits, from simple names like "Bat Groening" or "Chains Hell Brooks" to complex ones like "David²+S.²=Cohen²". Sam Simon, who left the show during the fourth season, still receives "developed by" and "executive producer" credits, and until "Treehouse of Horror XXII", he had been listed in Treehouse of Horror episodes as "Sam 'Sayonara' Simon" and between "Treehouse of Horror XXII" and "Treehouse of Horror XXV" as "simonsam@TWITterror". However, following his death in March 2015, he has simply been credited as "Sam Simon" starting from "Treehouse of Horror XXVI". The idea for "scary names" came from executive producer Al Jean, who was inspired by EC Comics because some of the issues also used "scary" alternate names. The "scary names" became such a burden to write that they were cut for "Treehouse of Horror XII" and "Treehouse of Horror XIII", but after hearing complaints from the fans, Jean decided to bring them back. Matt Groening's rule for the "scary names" is that they cannot be longer than a person's real name, but this is rarely followed by anyone else. Cultural references References to films, novels, plays, television shows, and other media are commonly featured, and many segments have been parodies of a specific work in the horror, science fiction, or fantasy genre. Many segments are spoofs of episodes of The Twilight Zone, and entire segments will be based on a single episode. Some of the Twilight Zone episodes parodied include "A Kind of a Stopwatch", "To