He'd probably work best in rain, although if you use Politoed for drizzle, Swift Swim would be illegal. Try this if you're not using Politoed, and if you are, just switch the ability to Poison Touch.
Seismitoad@Life Orb
Modest Nature [+SpA; -Atk]
Ability: Swift Swim
EVs: 132 HP / 4 Def / 156 SpA / 4 SpD / 212 Spe
- Hydro Pump
- Hidden Power [Ice]
- Grass Knot
- Earth Power / Protect
He should be rather decent. :] You can probably run Lefites >> Life Orb if you really feel like it because he's rather bulky.