The title of this article is conjectural. Though the topic is found within The Simpsons universe, a proper name is not available.
The Squashed Bart couch gag is the first couch gag of Season 1. It is also the first couch gag ever used in The Simpsons.
The Simpsons sit on the couch, but Bart gets squashed and shot into the air. He reappears six seconds later falling in front of the television (in FXX airings of Bart the Genius only the thud is heard, Bart falling or the TV shaking cannot be seen)