You'll need the SquirtBottle. To get that you'll need to talk to the girl who is south of Sudowoodo and she'll tell you to go with her to Goldenrod City and once you get there go into the Flower Shop on the corner right up. Her bigger sister will give you the Squirtbottle.
Sudowoodo
you can catch sudowoodo and smeargle
Sudowoodo can be found after you defeat the elite four. Sudowoodo is located at south-eastern area of the Battle Frontier.
Use the wailmer pail on it it will attack you make sure you catch it only emerald and Pokemon colosseum can get a sudowoodo.
You can't, you either have to trade a purified Sudowoodo from Pokemon Colosseum or trade the one you catch in the Battle Frontier from Emerald.
If you count sudowoodo as a legendary then yes
soodoowoodoo level 30
sudowoodo
it's a sudowoodo, water it with the wailmer pail, get that in rustboro flower shop
No you will need Emerald or Pokemon Colosseum to trade you a Sudowoodo.
No, but it is considered as a rare Pokemon in emerald.
If it helps, Sudowoodo doesn't like water. In Pokemon Crystal, you get rid of Sudowoodo with a squirtbottle. As you haven't got that now, the next best thing is probably a water-type pokemon. No guarantees though.