Poliwrath

         

Poliwrath has tough muscles that make it able to swim across the Pacific Ocean nonstop.  It easily beats human swimmers by a long shot.  Despite Poliwrath being a good swimmer, it usually lives its life on land.

Poliwrath is a good Pokemon.  It doesn't have high or low stat amounts.  Just in between.  It's usually great, but it doesn't work out for everybody.  Base HP is 90, Attack is 85, Defense 95, Sp. Attack 70, Sp. Defense 90, and Speed is 70.  For a Fighting-Type, one would expect a higher Attack stat- but now Poliwrath could be great whether it is Physically based or Specially Based.
Poliwrath has several good STAB moves.  Submission, Hydro Pump, Surf, Water Pulse, Scald, and so on.  It has Dynamicpunch, which has high base power and causes confusion to the target when it hits.  But it has a low accuracy, so give it Mind Reader.  Mind Reader ensures that the next move that you use will hit its target.  It works good with moves that have low accuracy.  Poliwrath can learn Endeavor, which is an awesome move.  If you use it, it brings down the target's HP down to as much as the HP you have.  Basically, the less HP you have- (not low HP stats, I mean low health where the meter is at red) the more powerful the move Endeavor has.  Poliwrath has several good moves available in its movepool.
Poliwrath's abilities are Damp and Water Absorb.  If any Pokemon has the ability Damp, no Pokemon can use Selfdestruct or Explosion, including your's.  It's an okay ability.  It's not the best, but it's acceptable, considering how powerful Selfdestruct and Explosion are.  Water Absorb means that you'll have your HP restored when you're hit by a Water-Type move.  I always say it's bad on a Water-Type because opponents just know Water moves don't do much to Water-Types.  However, Water Absorb can still be useful on occasions. 
Poliwrath is a good Pokemon.  I've always liked its design, and it has a good movepool.  It just doesn't have the highest stats.  It isn't the best, but it's a useful Pokemon overall.