Ho-oh is the legendary Rainbow Pokemon. It lands upon the top of the Tin Tower in Ecruteak City when you have the Clear Bell and the Rainbow Feather. In Heart Gold version, you get the Rainbow Feather after beating all the Johto gyms and challenging the Kimono girls in Ecruteak City. In Soul Silver version, you get the Rainbow Feather from a man in Pewter City in Kanto.
Lugia is the legendary Diving Pokemon. It lies at the bottom of the Whirl Islands between Olivine City and Cianwood Island (Route 41) when you have the Clear Bell and the Silver Wing. In Soul Silver version, you get the Silver Wing after beating all the Johto gyms and challenging the Kimono girls in Ecruteak City. In Heart Gold version, you get the Silver Wing from a man in Pewter City in Kanto. You may want to use the top-right entrance of the Whirl Islands to get to Lugia.
Suicune is the legendary Aurora Pokemon. When the Brass Tower (now the Burnt Tower) burnt down, a Pokemon perished and was resurrected as Suicune by Ho-oh. Suicune runs away to various parts of Johto and Kanto. To fight it in a battle, you must meet it at all of the following in order:
- Burnt Tower (Where it first runs away)
- North of Cianwood Island
- The Route around Mt Mortar on the way to Mahogony (Route 42)
- Vermillion Port
- Route 14
Entei and Raikou
Entei and Raikou are the two other legendary beasts resurrected by Ho-oh. When you meet them at the bottom of the Burnt Tower in Ecruteak, they will flee. They will then appear on your Pokegear map, though they will move every time you go to a different area. When you do see them, they will flee after the first turn, but will retain any damage dealt to them.
Articuno is one of the three legendary birds of Kanto. After you get 16 badges it can be found at the bottom of the Seafoam Islands between Cinnabar Island and Fuschia City in Kanto.
Zapdos is one of the three legendary birds of Kanto. After you get 16 badges it can be found in front of the Power Plant on Route 9.
Moltres is one of the three legendary birds of Kanto. After you get 16 badges it can be found in Mt. Silver.
Mewtwo is the legendary Pokemon generated from Mew's genes. It vanished into Cerulean Cave where it can be found currently. You need to have beaten all 16 gyms before entering this cave.
Latias and Latios
Latias and Latios are the legendary Eon Pokemon. When you speak to Copycat in her pink house at Saffron City after beating Red, her doll is missing. You have to visit the Fan Club in Vermillion. When you talk to the man at the table, he will give it back to you. When you leave, you bump into Steven Stone. He then shows you Latias if you are playing Heart Gold, or Latios in Soul Silver. At that point, they are found in your PokeGear like Entei and Raikou, except they roam Kanto only.
Groudon and Kyogre
Kyogre and Groudon are the legendary titans of the sea and land. After beating Red, they can be found in the Embedded Tower on Route 47 after obtaining their orbs. Kyogre can only be found in Heart Gold version, and Groudon can only be found in Soul Silver Version. Depending on your version, if you go to Mr. Pokemon's house on Route 30, he will give you the correct orb that will allow you admittance into the tower.
Rayquaza is the legendary Sky Pokemon. When you get Kyogre and Groudon into the same game, by trading the one not found into it, bring then both to Professor Oak in Palette Town. He will give you another orb which, when brought to the Embedded Tower, will let you battle Rayquaza.
Dialga, Palkia, and Giratina
When you activate the Arceus event in the by bringing an Arceus to the Ruins of Alph, you are brought to the Shinjo Ruins where you meet up with Cynthia. You are given the choice of one of these Sinnoh Legends to hatch at level 1 (You do not get an egg).