妳看那英文解釋：
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.