For running comic strips, the equivalent term “marring Irving” was coined in 2005. That phrase comes from the comic strip Cathy, a strip with a title character who was a confirmed bachelorette for nearly 30 years before she married Irving Hillman; the strip ended its run five years after the marriage.
A particular subset of the “jumping the shark” phenomenon, in which key members of the writing staff either die or leave the strip and are replaced, is known as the zombie strip.