Available in the main game:
* Articuno: Ice/Flying
* Zapdos: Electric/Flying
* Moltres: Fire/Flying
* Mewtwo: Psychic
* Mew: Psychic
Available through events:
* Raikou: Electric
* Entei: Fire
* Suicune: Water
Note:
* The Legendary Birds (Articuno, Zapdos, Moltres) are found in the Sevii Islands, which are accessible after completing the main game.
* Mewtwo is found on Cinnabar Island after defeating the Elite Four.
* Mew is a mythical Pokémon that is only obtainable through specific events or glitches.
* The Legendary Beasts (Raikou, Entei, Suicune) were originally obtainable through events in the original Pokémon Gold and Silver games. While they are not officially obtainable in FireRed, some players may have access to them if they traded them from older games or obtained them through specific methods.
Remember that obtaining these Pokémon requires specific steps and may involve trading or specific event codes.