The couch gag is a running visual joke in the opening credits of the animated television series The Simpsons. The couch gag changes from episode to episode, and usually features the Simpson family's living room couch. A typical gag features the Simpson family running into the living room, only to find some abnormality with the couch; be it a bizarre and unexpected occupant, an odd placement of the couch, such as the ceiling, or any number of other situations. In more recent seasons, the couch gags have tended to be more outlandish and absurd. (...)
Originally airing on March 25, 2007 the episode "Homerazzi" used a prolonged couch gag where Homer is the basis of about a dozen organisms depicting the mankind's evolution. When he walks upright, Homer walks through a few period scenes before walking through the Simpsons' front door to sit down on the couch (Marge asks 'What took you so long?'). By the time this episode had aired on the East Coast, the show's message board at the Internet Movie Database had several threads declaring this the best, or greatest, or most innovative couch gag in the series' history. This sequence is clearly inspired by the music video for the Fatboy Slim track Right Here Right Now in both the larger idea and smaller details.