In Pokemon Y you can catch 4 Legendary Pokemon. They are Yvetal, Mewtwo, Zygarde and one of the Legendary Birds depending on which starter you chose.
- If you choose Froakie you can get Moltres
- If you choose Chespin you can get Articuno
- If you choose Fennekin you can get Zapdos
Yvetal can be caught while playing through the story. You get the opportunity to catch Yvetal after you obtain your 8th badge.
Mewtwo can be found at the end of Unkown Cave only after you have beaten the Elite Four.
Zygarde can be found at the end of Terminus Cave only after you have beaten the Elite Four.
Moltres, Articuno and Zapdos can be found roaming after you have beaten the Elite Four. You must use your Pokedex to Pin-Point the Birds and encounter them 10 times and then they will appear in the Sea-Spirits Den where you will be able to catch them.
As for the other Legendary Pokemon like the Legendary Dogs or the Main Legends from other Pokemon titles won’t be in the game until the launch of the Pokemon Bank on December 27th, so if you really want to complete your Pokedex before then it can be done! But it will cost you some Poke Dollars. All you have to do is go to any of the Cafes in Anistar City, Laverre City or Cyllage City and pay 5000 Poke Dollars to be seated in the Terrace. After you are served and or leave a tip, talk to the other person in the Terrace and they will show you a Pokemon and add it to your Pokedex. They won’t always show you a legend but they will occasionally. I’ve done it about 5 times and I’ve gotten Suicune added to my Pokedex!
The first thing you are going to want to do is go to the Pokemon Center in Lumoise City in the South Boulevard and talk to the man in the suit just to the right of the Nurse. When you talk to the man he will ask you if you want to trade Poke Miles for prizes. One of those prizes are the rare candies! The rare candies cost 500 Poke Miles or 250 Poke Miles if you buy them through the Pokemon Global Link Website.
Earning Poke Miles
There are 2 ways of earning Poke Miles: StreetPassing other people playing Pokemon Y or through trades. Usually when you StreetPass someone they live around you so you will probably get less than 5 Poke Miles, so your best bet is trading Pokemon. While in the GTS you can choose which region the other player is from so that is one way to earn lots of Poke Miles but you will need the Pokemon that the other player is asking for. But the best way for earning Poke Miles is through Wonder Trade. I recommend going to Santalune City with some Ultra Balls and catch a bunch of the lower level Pokemon around there. Then once you’ve caught a few of the low level Pokemon, go to the Player Search System on your bottom screen, PRESS the start button and click on the Wonder Trade button, then trade the low level Pokemon you just caught until you receive a Pokemon you want to keep, then you move onto the next Pokemon and continue this process! I honestly love Wonder Trade because it helps you expand your Pokedex and it gives you Poke Miles too!