You have to beat elite four and have of over sixty different Pokemon and the you will get the national poke dex and one will be in there. The one you'll see will vary on what starter you chose at the beiginning of game. Sorry about spelling
You can only catch one of the dogs which depends on what starter you chose to get the rest get one from firered to get the second and the third from Pokemon colosseum.
Do you mean legendary dogs? Entei, Suicune, Raikou. Well if you start with Squirtle Raikou will be wild when you have beaten the Elite 4. Same with Charmander(Suicune) and Bulbasaur(Entei).
transfer them from Pokemon coliseum or xd
You dont
dont think
migrate from firered and leafgreen
Trade from Pokemon leafgreen or firered
no you cant and how would that even work.
you run into them randomly anywhere you can only get the one according to your starter Bulbasaur: Entei Charmander: Suicune Squirtle: Raikou
None of the legendary dogs are available in Emerald you must obtain them from Firered, Leafgreen, or Pokemon Colosseum.
you cant get or find any rare dogs without cheats
in firered and leafgreen, yes. after beating the elite four, go back to route 1.(that's where the legendary dogs are most likely to be found). have your master ball handy! run around in the grass until you find it. which legendary dog you get depends on your starter. if your starter is bulbusaur, you will find entei. charmander-suicune, and squirtle-raikou.