The title of this article is a conjectural. Though the topic is found within The Simpsons universe, a proper name is not available.
The Matrjoschka couch gag is the third couch gag of Season 9.
Homer runs in alone and stands in front of the couch. The top half of him pops off and on to the couch revealing a smaller Marge standing inside the lower half of Homer, like a Russian nesting doll. The top half of Marge pops off revealing Bart, whose top half pops off revealing Lisa, whose top half finally pops off to reveal Maggie, who stays in the middle of Homer’s body and sucks on her pacifier