Season 4, Episode 22: Krusty Gets Kancelled
In this episode, the residents of Springfield suddenly start seeing advertisements for something called Gabbo. Nobody knows exactly what it is, but people are constantly seeing commercials, headlines, and other advertisements letting them know it’s coming soon. While out driving, Mr. Burns and Smithers pass a “GABBO is Coming” billboard, which Mr. Burns misreads.
I’m sure Mr. Burns was very disappointed to find out Gabbo was actually just a ventriloquist dummy.