A couch gag is a visual joke in the Opening Sequence of The Simpsons. The couch gag changes from episode to episode, rarely repeating, sometimes with the placement of the couch changing. In more recent seasons, the couch gags have tended to be more outlandish and absurd, sometimes showing the Simpson family sitting on the sofa in different types of media (claymation, live-action, flipbook animation, etc.). Generally, between one-half and two-thirds of the couch gags used in a season are new, while the remaining are repeats. Most couch gags are used at least twice, with a second occurrence usually in the same season as the first. However, as of Season 21, couch gags are rarely reused.