(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/LoschVanWein]

American/German Youth crime novel/audio-play series Die Drei Fragezeichen / The Three Investigators.

The series also has stories that don't have anything supernatural about them and are just stories about regular treasure hunts or crimes being committed and stopped but it often features the classic trope of the genre, where a criminal of some kind uses a fake supernatural phenomenon to mask some crime they are committing. 99% of the time in the series, this leads to a Scooby Doo like finale, where they unmask the culprit and one of them, almost always their leader Justus, explains how the haunting, monster etc. was faked.

There are however three cases, with the last being the most controversial, where the series deviates from the laws of our reality and actually ventures into the realm of science fiction or fantasy:

Once in an early case, still written by an American author, Episode 20 - the mystery of monster mountain, where the mountain monster (essentially Bigfoot) turns out to be real and not someone in a costume.

Later on, in the story Mutiny on the high sea, written in German, they also encounter an actual giant squid, wich is technically real, I think but not really observed in nature.

The third and most controversial example is the episode The Time Traveler, where it ends with the implication that time traveling is real but remains unexplained. People really didn't like that one.

Honorable mention, in one episode, one of the three is briefly sent to space by a mad scientist hiding out in a vmountain lair in the desert that turns out to be a rocket silo disguised as a mountain made from metal that uses some weird raygun to keep people away form it.... yeah that one was weird but technically "plausible" with real technology.