Well first you have to finish the main story line.Also it depends on what your starter was,Charmander=suicune Squirtle=entei Bulbasaur=rikou but I may be wrong on that so look that up on its own.THANKS!
The legendary dog you find the dog that has a type advantage over your starter.
Raikou is a legendary dog Pokemon. It is not in any specific location in Pokemon Fire Red. Instead, you can find it roaming Sinnoh.
You would have had to chosen Charizard as your starter Pokemon. Whichever legendary dog appears depends on your starter. You will find your legendary dog randomly in the wild. (you must beat the elite four first)
Entei, Raikou and Suicine are often referred to as the Legendary Beasts or Legendary Dog pokemon. They aren't in Diamond, so you'll have to trade or migrate them. You can do this from the following games: FireRed/LeafGreen, HeartGold/SoulSilver and OmegaRuby/AlphaSapphire.
just go to the pet shop and buy all of them.
they roam around in the wild after you have done everything on the islands but they run away
to get it u need to have charizard.to get suicune use max repel and if a Pokemon appears its suicune!
You can find a (as in only one of) the legendary dogs roaming your game after you have completed the national dex. You will get whichever dog is supereffective to your starter. Raikou-----> Squirtle Entei------> Bulbasaur Suicune---->Charmander
Entei, raikou and suicune the three legendary dogs? Well in firered yes you can capture only one of these and it depends on the starter Pokemon you chose, bulbusaur=entei, charmander=suicune, squirtle=raikou. So after beating the elite four getting the national dex and delivering the ruby and sapphire to celio you can find your legendary dog on route 1 in the grass just use the masterball when it does show up.
the fire Pokemon that professor oak give ( charmander ) and also growthlite ( a dog Pokemon ) Forgive me if spell wrong
Find it on a route in the grass then use the masterball.
It's highly recommended to use it on your legendary dog Pokemon whether it's Raikou, Suicune or Entei.