To read about any crossover, cameo or reference between two series, search for the name of the two series with an uppercase "X" between them. For example to read about interactions between the Mario series and the Zelda series, look for Mario X Zelda. (It reads "Mario cross Zelda")
NOTE: this Wiki is not to read, or write about fanfiction or mods,
but to read or write about official cameos and crossovers!
To be sure to fully understand how crossovers work on this Wiki, be sure to read the pages in the Crossover rules category, especially the Series and Link pages.
...that Tamagotchi m!x: Sanrio Characters m!x Ver. is a Tamagotchi game including various Sanrio characters, such as Hello Kitty which allows players to couple characters from the different series together, giving birth to hybrid children?
January 15th 2021: DC and Rooster Teeth announce an official comic crossover between RWBY and The Justice League.
Each series that crossed over to another one has its own article featuring some basic information, a list of releases and, most importantly, a list of links to other series. To learn more detailed information about a single series, check out the links to series specific wikis in each page.
Would you believe that all these series are connected to each other through subsequent crossovers?
Link pages explain in detail every crossover that happened between two series and are named [Series A] X [Series B]. (For example the page Wario X Zelda lists all crossovers that happened between the Wario series and the Zelda series). Links are classified in three types on this wiki:
You can follow an existing page's formula, like Mario or other pages in the series category. Also you might want to read the series page to see what we consider a series.
If you want to write about a crossover or reference between two series you can follow the existing links pages. Also you might want to read the link page to see how to properly classify these links.
The goal of this project is to create a chain of crossovers between series, so it is best to start from existing series and expand in any direction trough in-universe links, but still, you can add everything you want to.
You're also free to add some extra information about single series, just don't go too deep with them, since every series' page has a link to the specific Wiki. Concentrate on giving the basic information, or information useful to fully understand the crossovers between series.