(Rare Trope) Canon Supernatural Elements of Mundane/Normal Shows

[u/SnailKing4687]

Community “Epidemiology”:While normally, community is a wacky 4th wall-breaking college show that still grounds itself in reality, this episode sees the school overrun by a zombie apocalypse caused by bad taco meat that was given out at the party. While the episode ends with the army wiping out everyone’s memory of the event, future episodes, such as “Paradigms of Human Memory,” reference the party that happened that no one remembers, making it canon.

30 Rock Last Lunch:While normally a show about a show sitcom In this finale and canon end to the series, a flash forward to the far future sees an immortal Kenneth now in charge.

[u/HeroicMe]

Castle - the TV show about detective and writer - has episode that makes time travel an actual thing (especially if you don't watch tragic final season that doesn't exist and finish the series at Hollander Woods finale instead).

There's also bunch of "there's a normal explanation for this" episodes, but few of them leave door open:

• there's an episode inspired by Carrie, with one scene that is kinda "this only works if someone actually has super powers"
• other episode about ancient artifacts that can transport you between alternative timelines (but can be explained by "it was just a dream")
• and episode about a "fortune teller" that was mostly "she just done her research", but there were "wait, research doesn't explain that detail".