Nobody. It depends on which starter Pokemon you chose
Charmander - Suicune
Squirtle - Raikou
Bulbasaur - Entei
a legendary Pokemon that is supposedely the god of Pokemon who in some next movie will try to take back what he has created. and he had created the hoenn region, the legendary Pokemon palkia and dialga, and also the three lake Pokemon mesprit,azelf,and uxie.
Entei, raikou and suicune
there is not one
Of the three original legendary birds, there is Moltres, and of the Johtolegendary birds, there is Ho-Oh.
it's 30% of recruiting them
Nothing happens after that. You just caught the three legendary roaming Pokemon in the Johto Region.
After you get the National Dex, talk to one of the PokemonProf. who will talk about three ledgendary birds. They will then be roaming around like Mesprit and Cresselia. Hope this helped.~
you have to beat the elite 4 again and then they will start roaming again and you can try 2 catch them. (:
Emrit' or 'Mesprit' is legendary Pokémon of the Psychic-type. It's one of the three 'Guardians of the Lake' of the Sinnoh region and appeared onward the fourth generation of Pokémon's. In the Diamond version of the games it can be found roaming around the Sinnoh region, where can be trapped if defeated.
Entei and Raiku can be captured through roaming after you see them at the burnt tower. If you follow suicune around Kanto and Johto, It appears at Bills house.
entei and riakou rome all around the johto region and suicune is just above cerulian city in the kanto region. For Leaf Green/Fire Red which legendary dog you can find depends on your starter.
I believe you have to beat the elite four and obtain the national dex. i think then after that you can find the birds roaming around like wild beasts :D
once you obtain the national pokedex you meet professor oak. eventually he goes to eterna city. talk to him there and he will activate the three legendary birds that will now be roaming sinnoh.
After you get the national dex go and talk to professor Oak in Pal Park than he will be in a house in lower left corner of Eterna city and he will say the legendary birds are roaming in Sinnoh than with the help of Marking app you can catch the three legendary birds
Platinum only (I haven't played Diamond and Pearl and I'm not sure if the three games are basically the same). Cresselia is a roaming Pokemon. After you encounter it in Full Moon Island, it will flee (leaving behind a Lunar Wing, which you'd use to wake the sailor's son up from his nightmare) and it will become a roaming Pokemon (which is like the legendary dogs in Crystal: it will move to random places in the region everytime you change routes). They can be tracked with the Marking Map app on the Pokewatch. It will appear as a flashing symbol which will randomly change places. If you are tracking a lot of roaming Pokemon at the time, there is no way of telling which legendary Pokemon is which on the Marking Map. If you are in the same place as the flashing symbol, go into any patch of grass or surf and the first wild Pokemon encounter should be the legendary one. Most legendary Pokemon have a special short song/piece but Cresselia has the normal wild Pokemon encounter song. Then, it's purely about luck.
you can get the three dogs bij free roaming through Johnto after you set them free at the Burnt Tower in Ecruteak City Suicune, however, can also be in Kanto but you can battle him at Bill's House in Cerulean City if you follow the story line
After obtaining the National Pokedex go to Professor Oak in Eterna City he will mention that the three legendary birds have been spotted nearby within Sinnoh. You will need the marking map as Moltres is a roaming Pokemon.