You cannot. You can transfer it from Pokémon Colosseum or Pokémon FireRed or LeafGreen (provided that your starter was Bulbasaur).
No you cannot catch Entei in Pokemon Emerald.
You can't catch entei in Pokemon black he is on a different version
suicune is a rubbish Pokemon, if ya want it its not in emerald, its in Pokemon silver gold ruby and sapphire, ( they got rid of entei raikou and suicune to make way for rayquaza )
Entei, Suicune, and Raikou are not available in Pokemon Emerald, Ruby or Sapphire. They can be brought into the game by trading.
No, you can catch Entei without catching Moltres.
You cannot catch Entei in Pokémon White because it is not available for capture.
Yes, You can catch Groudon in Pokemon Emerald.
You can't catch one in Pokemon Emerald.
Entei!!!
You can't catch a Bellsprot in Pokemon Emerald. You trade it from Pokemon Leafgreen!
you cant catch entei on Pokemon pearl. entei is a johto Pokemon and Pokemon pearl is a sinnoh game. the only way to getentei is to trade it over from another game games compatible are Pokemon diamond, Pokemon platinum, Pokemon soulsilver and Pokemon heartgold. the last two i am sure you can get entei. (i have seen it in the wild)
There are many Pokemon you catch that are similar in sapphire and emerald but there are many Pokemon emerald can only get and not sapphire.