Nowhere, you need to breed Poliwhirl/wrath/toed.
You can't catch a poliwag in Pokemon Sapphire. You have to trade from Pokemon Fire Red or Pokemon Leaf Green.
I'm sorry, but you will have to trade from Pokemon LeafGreen or FireRed. There is no way to find a Poliwag in the wild in Emerald.
You'll need to trade for it.
surf on water or get a fishing rod
Nope, you have to fish.
poliwag is usually on the beach.
You can find poliwag at: Silent Chasm 5-9, Northwind Field 1-4, Waterfall Pond 1-5 (8.1%)
Shiny Poliwag can be anywhere in water, but you would have a very very very little chance of finding it.
The route between Cherrygrove and Violet city
to get a poliwag, you must obtain a good rod or a super rod. next, fish in cerulean city or the lake near vermilion. they are the most common places to find poliwag. hope this helps!
You can find Pidey in a Pokemon Outbreak in Pokemon Diamond
Poliwag evolves into Pilowhirl which then evolves into Poliwrath