After you beat Whitney go to the flower shop in goldenrod then she will give you a squirtbottle then you go to the road towards ecruteak city and sudowoodo will be blocking your path talk to it and than your character will squirt the bottle then you battle sudowoodo and its at level 20
Chat with our AI personalities
After you beat the Goldenrod City gym, you need to get a watering can from the building next door. Use this on Sudowoodo and you will be able to battle it.
The same place you find him in gold, north of Goldenrod City. You have to beat Whitney and then get the Squirtbottle from the house behind the gym. Use it on Sudowoodo and he will attack you.
sudowoodo
No you will need Emerald or Pokemon Colosseum to trade you a Sudowoodo.
You must learn rock smash. You get that from a man standing in the right of you you when you have beaten sudowoodo