Mew is not catchable in Pokémon X or Y.
You must either trade for it or transfer via Poké Transporter and Pokémon Bank from an older game.
Someone hacked the game and found Mew in the code, but it is currently not possible to get it (without hacking).
*Mew is not catchable in Pokemon x and y, but you can get him online from wondertrades and such. Mewtwo however, is catchable and you can find him in the cave in pokemon village.
It's catchable in Red/Blue/Yellow, FireRed/LeafGreen, HeartGold/SoulSilver, and X/Y. You catch it in the Cerulean Cave in Cerulean City in Red/Blue/Yellow, FireRed/LeafGreen, and SoulSilver, and the Unknown Dungeon in the Pokemon Village in X/Y.
Mewtwo cannot evolve, but it can mega evolve temporarily in Pokemon X, Y, Alpha Sapphire, and Omega Ruby by letting it hold a Mewtwonite X or Mewtwonite Y.
haha mew 3 isnt a pokemon i reapeat is not real mew 3 is actual the newest version of mewtwo in fact i dont think you can even get mew or mewtwo but you can trade for a mew from pokemon x or y of firered of leafgrean or dark cry versions
No, Mewtwo cannot evolve into Mewthree. Mewthree isn't an existing Pokémon however Mewtwo can use a Mega Stone in Pokémon X and Pokémon Y in order to mega evolve during battle into MegaMewtwo.
In order to get Mew in Pokémon X and Y, you must transfer it from any Generation V game (Pokémon Black, White, Black 2 and White 2) through the Poké Transporter once the Pokémon Bank is released in December 27th, 2013 or ask someone to trade you one after this date. It's currently unknown if there's going to be a Mew give-away event for Pokémon X and Y.
Aron is unobtainable in Y, but you can use the GTS to trade one for a larvitar, the Y counterpart to a user of X.
You can catch Mewtwo at the Unknown Dungeon after beating the Elite Four and entering the Hall of Fame.
It is A A A B B B Y X Y X B L+R X
In terms of Legendaries, most of the ends of the caves in Pokemon X and Y (Like the Sea Spirit's Den in the Azure Bay near Korrina's town
Yes You Can Get A Pikachu In Pokemon X and Y.