Yes you can.
# Articuno # Zapdos # Moltres # Mewtwo # and one of three legendary dogs (depending on your starter Pokemon)
The three legendary birds, moltres zapdos and articuno and mewtwo and one of the three legendary dogs depending on your starting Pokemon and deoxys
Only by trading them from Gold, Silver or Crystal.
You cannot get Legendary Pokémon Eggs in Pokémon LeafGreen due to Legendary Pokémon being incapable of breeding.
You cannot catch Registeel in Pokemon LeafGreen. This is due to FireRed and LeafGreen being able to trade with Ruby and Sapphire. Pokemon Ruby and Sapphire have the three legendary golem Pokemon including Registeel.
there are 5 legendary Pokemon in leafgreen version
There are multiple legendary pokemon. But there isn't one that the game focuses on.
Manaphy is a legendary water type of Pokemon. It is not possible to get this Pokemon in the game Pokemon 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.
zapdos moltres articuno and mewtwo
The legendary birds are: Articuno, Zapdos, and Moltres.
the three legendary cats, after you beat the elite four, one of them (depending on which starter you chose) will randomly appear in the grass. By the way, they are the legendary cats, not dogs. The Pokemon Company revealed that Raikou is a tiger, Entei is a lion, and Suicune is a cheetah.