Impossible without cheating.
Trade a Clamperl with a Deepseascale.
Only by trading with a friend.
huntail has more attack and gorebyss has more defense
GameShark is the only other way.
Not without trading from another game or using cheats.
you have to get 150 different types of Pokemon
you cant sorry - Raymond laduke
You can't without trading, migrating or, cheats
It is impossible to get all three starter Pokemon in one game without trading, unless you are willing to use an Action Replay.
You can get seviper from Pokemon sapphire by trading.
The legendaries you can catch in Pokemon Ruby without trading or going to an event are Groundon, Rayquaza, Latios, Regice, Regirock, and Registeel.
The best team you can possibly get in Pokemon Ruby would probably be:SwampertGroudonAggronFlygonGardevoirLinoon (For item pick up.)