[[quoteright:300:[[WesternAnimation/TheSimpsons http://static.tvtropes.org/pmwiki/pub/images/homers.jpg]]]]
[[caption-width-right:300:[[MeetYourEarlyInstallmentWeirdness Let's all go out for some frosty chocolate milkshakes.]]]]

A Mythology Gag is a sort of Meta-ContinuityNod, wherein a reference to some facet of a show's mythology or past production history (which is not actually considered {{Canon}} in the context of the show) is made. This trope is usually taken largely as a bit of gratuitous humor, since if the program you're watching is "real" then the characters shouldn't be thinking in terms of ''any'' continuity, alternate or otherwise. (Sometimes this will be hilariously [[LampshadeHanging lampshaded]] by the characters, who wonder how they could possibly know such a thing. Also, the CelebrityParadox might come into play.)

Often seen in {{Revival}}s, [[ContinuityReboot Reboots]] or {{Series Franchise}}s, when an element from the previous version of the show (or from the previous show in the SeriesFranchise) is referenced or seen in some way. This is usually done as an acknowledgment to the fans of the first incarnation of the show. When successful, serves as a reassurance to those fans that the producers aren't trying to disrespect the original source material. When unsuccessful, only reminds fans that the original source material essentially never happened. The success of the Mythology Gag is always a matter of opinion.

See RemakeCameo for when the Mythology Gag involves actors from the original production. Compare to: ContinuityNod, DiscontinuityNod, RecurringElement, IWantYouToMeetAnOldFriendOfMine, ActorAllusion, ContinuityCameo, AscendedMeme, MeetYourEarlyInstallmentWeirdness (when taken a step further) and ShoutOut. Contrast DevelopmentGag, which references things that ''would'' have been part of the work but were left out halfway through production, and EarlyBirdCameo.

* MythologyGag/{{Anime}}
* MythologyGag/CardGames
* MythologyGag/{{Comics}}
* MythologyGag/FanFic
* MythologyGag/{{Film}}
* MythologyGag/{{Literature}}
* MythologyGag/LiveActionTV
* MythologyGag/{{Music}}
* MythologyGag/{{Pinball}}
* MythologyGag/{{Radio}}
* MythologyGag/TabletopGames
* MythologyGag/{{Theater}}
* MythologyGag/{{Toys}}
* MythologyGag/VideoGames
* MythologyGag/WebComics
* MythologyGag/WebOriginal
* MythologyGag/WesternAnimation