There roaming around kanto to find them have someone trade you the dog you are going to catch so lets say you picked bulbasaur as your starter you want to get an entei from somewhere because your going to catch it and to see where it is you check its area on the pokedex and the red area is where it is but it will move to stop it from moving use sweet scent outside of battle to lure it to you. You can only catch one dog so you need to get the others from Pokemon colosseum or a Pokemon fire red or another leaf green.
no you can not
There not in cerulean cave.
Only by trading them from Gold, Silver or Crystal.
# Articuno # Zapdos # Moltres # Mewtwo # and one of three legendary dogs (depending on your starter Pokemon)
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.
The three legendary birds, moltres zapdos and articuno and mewtwo and one of the three legendary dogs depending on your starting Pokemon and deoxys
Yes you can.
migrate from firered and leafgreen
There are only three legendary Pokemon you can obtain that change depending on which starter you choose: the three dogs. If you start with Charmander: Suicune If you start with Squirtle: Raikou If you start with Bulbasaur: Entei I hope that helps.
Trade from Pokemon leafgreen or firered
trade from emerald
There is no Mew 3.