This episode is considered non-canon, and the events featured are not part of the timeline of the series' continuity.
I, Carumbus is the second episode of Season 32, originally produced as an episode of Season 31.
At a museum exhibit of Ancient Rome, Marge and Homer get into an argument about Homer's lack of ambition. They then imagine a Roman version of what would happen if Homer was more career-driven.
At a museum exhibit about Ancient Rome, Homer complains that he should have gone to a career improvement at the power plant. Marge gets rattled and says that Homer should have more ambition. A fight begins, but a museum worker soon interrupts telling about Obeseus the Wide, who had a big ambition.