Where do you catch Slowpoke in LeafGreen?

You can't catch Slowpoke but you can trade a Pokemon for a Slowbro somewhere. I think...I'm not sure...If you do happen to find it please tell me! Have you checked your Pokedex?

Use this site tell you where you can find the pokemone and what other game has it if you want to trade it: http://www.serebii.net/pokedex-rs/079.shtml