to catch articuno you use a ultra ball it is hard so bring a lot also you can use a great ball but that will require a lot of patience good luck buddy.
Use a master ball.
first you must hurt him and then you can catch him with ultra ball but he may use recover then you must hurt him again then you can catch him with ultra ball and 5% possibility to catch him with pokeball
use ur master ball NOTE ONLY IN LEAF GREEN AND FIRE RED
you cannot catch a Pokemon without a ball...however you can get Pokemon through trades or from another trainer in the game
You catch them with a ultra ball
get a Pokemon with the ability sound proof or a Pokemon with arena trap so he cant run
master ball
If you are in battle with another trainer you cannot catch that Pokemon that belongs to them. But if you find out where that Pokemon's habitat is (by using the pokedex) then you can go and catch it with a poke ball, great ball, ultra ball etc...
jiroxy ball...
Any Pokeball can catch Mewtwo. Weaker Pokeballs just have a far lower chance of catching him.
in Pokemon silver you can catch Pokemon as how you catch in other versions. in the Silver version is where the use of special Poke balls were introduced just like Fast Ball, Heavy Ball and Lure Ball.
Throw a Bait then throw him a Rock.Do that two more times.Throw a ball catch him