You can't catch wild Poliwhirl. You catch Poliwag though. Evolve your cute Poliwag into Poliwhirl by using a water stone. You can probably buy water stones in the department store in Celadon City.
Chat with our AI personalities
Meowth is not in the wild in Pokemon Yellow. You have to trade to get it
You can't get it, unless you train a Pokemon to level 100. The highest level wild Pokemon is arceus which is lv80, and you need an event for that, but without and event you can only get an lv47 Dalgia/Palkia for the highest level wild Pokemon.
The King's Rock causes Poliwhirl to evolve into Politoed, when traded holding it. It also causes Slowpoke to evolve into Slowking, when traded holding it. It can be obtained at Slowpoke Well, from wild Slowbro, and Poliwhirl, and the Pokeathlon dome.
A wild horsea has a 5% of holding a dragon scale. poliwhirl has a 5% chance of holding a king's rock.
No, you can just train your Pokemon against wild Pokemon to level up. But it's a little quicker going against the elite 4 cos their Pokemon are higher level than wild Pokemon.