I don’t think this is the first X-Men/Mario crossover, and I doubt it will be the last, but it is pretty damn cool nonetheless. The series of prints (all assembled at once for your viewing pleasure) show various Mario character with specific mutations. They all match up pretty well, but Rogue/Yoshi is a bit out of nowhere.
Where Juggernaut Bowser? Blob Wario? Perhaps more are on the way. Artist’s info coming when I manage to track it down.