No, there's no known glitch to catch another trainer's Pokémon.
In Pokemon emerald and other Pokemon games bad eggs are glitch Pokemon called missingNo. that will mess up your game if you catch them.
You can only use the hack, glitch, or Gameshark. I don't know any other way.
One method is to do the Missingno. glitch (where you talk to the man in pewter and let him catch Pokemon and then surf on the right side of cinibar island) and look around. along with meeting missingno. you may and I mean MAY find blastoise. you also may find other Pokemon like mewtwo and stuff.
By trading only. These Pokemon are unobtainable by any other natural gameplay, unless you used the Mew Glitch, which you would need to find certain trainers to activate the Pokemon you would want to catch. For more information on the Mew Glitch, just Google it or something, or go to Gamefaq's, and search the glitch guides, FAQ's, something.
In Pokemon Red, Blue, and Yellow you are able to catch Mew through a glitch. Mew is available in other games such as FireRed and LeafGreen, but it was an event Pokemon. The event it over, and all you can do is wait for a future event, or trade with someone who has Mew.
i do not think that you can.... maybe if you can find a random glitch or something you can.... if you trust the glitches.. :(
no but if you catch all the hoenn pokemon you can catch jotho and kanto pokemon
Never in any game of Pokemon can you catch every Pokemon on one version of the game you must use the other versions to get the rest. Unless you cheat but don't its not worth it.
You can use a Action Reply codes to catch other trainers pokemon.
You can't catch other Trainer's Pokemon. It is not an intentional feature in the website.
you cannot catch a Pokemon that is already owned by another trainer. you can only catch wild ones.
You are not allowed to catch other trainer's pokemons on any of the Pokemon games. You may only catch Pokemon from the wild or receive them through other means (events, game corner, eggs, etc.)