Ok, first legendary is articuno he is in sefoam islands you need surf,strength and rock smash. Second is zapdos he is in the power plant. The power plnat is where you first start at rock tunnel. You need surf. Third is moltres he is at the top of mt. ember. You need surf,rock smash and strength. Mewtwo is the last one. First you need to beat the elite four get the ruby and sapphire and give it to celio on one island. After that go to cerulian city and go to cave where that old lady WAS blocking. Inside of it is mewtwo get 30 ultra balls for mewtwo and 20 for moltres,articuno and zapdos. Also the dogs are wild in kanto. After you beat the elite four. SAVE BEFORE YOU BATTLE MEWTWO, ZAPDOS, MOLTRES AND ARTICUNO. DON'T USE YOU MASTER BALL ON MEWTWO OR ANY OF THE BIRDS. USE IT ON THE DOG. GOOD LUCK!