If you’ve ever visited a wiki site other than Wikipedia, it was probably run by Wikia, a site that allows anyone to create and run their own full Wikipedia-style site, for good or for ill. Perhaps their best-known spinoff is Wookieepedia, a Star Wars wiki that is by far the most complete and comprehensive source of Star Wars information outside of Lucasfilm itself, with 117,811 articles as of this writing. And it’s not just huge, lore-filled franchises either; Wikia’s 335,281 (and counting) communities range from a Wallace and Gromit wiki, to a wiki for the Oscars, to a wiki about buffalo nickels. “The 1913 Type 1 (or variety 1) Buffalo Nickel is the first pereoid of 1913,” proclaims this wiki. “This video may also tell you bits and pieses of the 1913 type 1 Buffalo Nickel.”
(fun fact: while looking through the Wikia movies hub I found an inexplicable description of/advertisement for a condo community in Florida that some confused soul had thought would be a good addition to a wiki about movie wikis)
But, like any content-focused Internet community that combines enthusiasm, the ability of anyone whomsoever to join, and a complete lack of moderation of any sort, Wikia gets more and more perplexing the deeper you go in. Take, for example, the fanon wikis.