History has not been kind to the Cousin Oliver Syndrome, with most shows that add a kid into the cast failing miserably either as a direct result of doing so or by the act itself being unable to stop the fall.

Source: https://collider.com/sitcom-kids-brady-bunch-modern-family/

This annoying little pipsqueak is basically the Cousin Oliver of animated characters.

Source: https://tvline.com/lists/worst-tv-characters-cast-additions-the-office-buffy-gilmore-girls/

We’re calling them the Cousin Oliver All-Stars, in honor of the patron saint of this category: the mischievous little tyke who got blamed for ruining when he arrived late in the series’ run.

Source: https://tvline.com/lists/worst-tv-characters-cast-additions-the-office-buffy-gilmore-girls/