I made a TN for Mewthree vs SSJ5 Goku and decided to expand the connections too
Two 2000's fanon characters who are extremely popular within the series's fandom, even more than some official characters. Both were only referenced through one line of the original but non canon works (Clefairy calling himself Mewthree after his DNA was mixed with Mewtwo's and Bulma saying that with the Blutz Wave Machine, Vegeta could possibly go Super Saiyan 5). Both were then discovered in extremely unexpected places (Mewthree in various Pokemon fan-sites and SSJ5 Goku in a Spanish Magazine) where they were given their iconic designs, which actually weren't theirs to begin with ("Mewthree" was just Mewtwo in battle armor from the first Pokemon movie and SSJ5 Goku's Design was actually meant for a Villain named "Tablos"). However, when the fans discovered these characters and made up a bunch of bullshit about them (Pokemon fans believing that Mewthree and other Pokegods would be in the next Pokemon game and DB fans making the Hoax that Dragon Ball AF was the Series after GT), they ran with the idea and made many fanworks with them, including one of the single most popular (& Infamous) fanworks in either fandom (Pokemon Chaos Black and The Many Versions of Dragon Ball AF (Mainly Toyble, Youngjijiji & Malik Torihane's Versions)) with these works mashing up alot of fandom ideas for the series into one. They are obviously the progressions for already existing characters (Mewthree being the next Mew clone and SSJ5 being Goku's next form). Both were meant to represent a new future for the series (Pokegods being the next-gen Pokemons and Dragon Ball AF being the Sequel Series to GT, with SSJ5 being it's Flagship form). Both are part of popular mods/romhacks for video games (Pokemon Fire Red for Mewthree and Budokai Tenkaichi 3 and Mugen for SSJ5 Goku). They are also known to fans as some of the most OP characters ever. Both have a number in their names (Three and five). Also, Mewthree is usually portrayed as being Mew's clone while SSJ5 Goku's most iconic opponent, Xicor, is the evil clone of Goku.