Mewthree? No. That thing's just a myth. And the guy who put this page up thought it was Mew's "final evolve". Mew and Mewtwo are two separate species. Mew does not evolve into Mewtwo people. Get over it.
Look at that picture. Why is it striking a Jackson pose? More importantly, why is it Level 3? That Electrode is going to completely dominate it. Some Legendary that thing is. Kinda of reminds me of Freeza. Maybe that's why Mewthree is genderless. I never could tell if Freeza was a dude or a chick.
But yeah, I'm done here. Mewthree is a fake and a joke. There can't be a Mewthree because Mewtwo blew up the scientists in charge of that stuff.