Poliwag @ Life Orb
Ability: Swift Swim / Water Absorb
EVs: 196 Atk / 116 SpA / 196 Spe
- Body Slam
- Earth Power
- Ice Beam
If you're using Poliwag on a rain team, use Swift Swim. If not, go with Water Absorb. Waterfall is STAB. Ice Beam covers Poliwag's Grass weakness, while Earth Power covers its Electric weakness. Body Slam is a solid move with a good chance of paralysis.