The rumor Mario and Rabbids crossover game has been leaked via an image released by Comicbook. This game is supposedly an RPG called Mario + Rabbids Kingdom Battle. According to the website the game is set to launch August of this year and will be revealed at E3.
According to both Koatku and Comicbook, the game will have turned based combat, co-op, and a wacky sense of humor. There are at least 8 characters: Mario, Luigi, Yoshi, Peach, and four Rabbids dressed as them. The game is also said to be launching for the Switch.
Although the game’s premise is bizarre, there have been numerous rumors and leaks concerning the game. Beyond the already mentioned sources there was Laura Kate Dale on twitter in January and a french gaming blog (English summary via Neogaf). Given the amount of information and sources confirming this game’s existence it is safe to assume it is real.