Pokémon Fire Red/Leaf Green each contain a number of legendary Pokémon. Their locations and levels are listed below. These are one chance Pokémon, so save before you fight them in case you knock them out as they can’t be found again!
Articuno can be found deep in the Seafoam Islands, which are located east of Cinnabar Island. You come across these islands as part of your adventure.
Zapdos is located at the end of the Power Plant. The Power Plant is located east of Cerulean City so you pass it early in your adventure but you cannot access it until you can surf.
Moltres is the only one of the legendary birds to have had its location changed from the original Pokémon Red/Green. Rather than being found in Victory Road it is now located inside Mt. Ember, which is on One Island of the Sevii Isles.
Mewtwo is located at the end of Cerulean Dungeon, which is only available after you beat the Elite Four. This dungeon is full of the toughest Pokémon in the game and Mewtwo himself is no slouch, so come prepared! It is recommended that you save your Master Ball for either Mewtwo or the legendary dogs.
Raikou / Entei / Suicine
The three legendary dogs will roam Kanto only after you beat the Elite Four. Only one dog will roam and which one depends on the starter you picked. They are all level 50. You can track them using your Pokédex’s location once you see them for the first time.
Ho-Oh is located on Navel Rock, which is a Sevii Island that can only be reached by using the MysticTicket, which was a special event giveaway. Ho-oh is located at the top of the tower, while Lugia is at the bottom. You can only pick one, so choose carefully.
Lugia is located on Navel Rock, which is a Sevii Island that can only be reached by using the MysticTicket, which was a special event giveaway. Ho-oh is located at the top of the tower, while Lugia is at the bottom. You can only pick one, so choose carefully.