An old Cartoon Network bumper (I'm talking from the Cartoon Cartoons era) that was a What-If.
In it, the narrator was talking about what would happen if a mailman wasn't there to do his job. Fred Flintstone wouldn't get a letter talking about a recall on equipment at his job so he apparently smashes up The Smurf's village. Papa Smurf gets abducted by a flyer and dropped on George Jetson's saucer, the two crash into Space Ghost's ship (which I think killed them both). Space Ghost's ship crashes, more disasters and death, until a bunch of CN characters are all charred in a hole where a vehicle crashed. Then someone hits rewind so that the mailman does do his job and none of it happened.
I did see that commericial again on YouTube this year. Problem was it was among a collection of bumpers and I don't remember which one it was on. Anybody have a link?