Corphish, the Ruffian Pokemon

Crawdaunt is a beastly attacker with his Dream World ability. With the proper breeding, he can wreak all sorts of havoc on your opponents. The build I suggest is the following:

Crabhammer
Night Slash
Dragon Dance
Aerial Ace/Superpower

IVs: 31 Attack, 31 Defense, 31 Speed
EVs: 252 Attack, 252 Speed, 4 HP

Have him hold a Focus Sash. The first turn you use Dragon Dance to boost Speed and Attack, and then you are set up to sweep most anything. The Adaptability ability changes the STAB from x1.5 to x2, meaning Crabhammer and Night Slash are 180 and 140 power respectively with no modification. After a single Dragon Dance, they become 270 and 210 respectively, and that is backed by Crawdaunts impressive base Attack stat of 120. Not only that, but with the right Nature, he becomes faster than most other Pokemon, pretty much anything under 110 base. Most things faster than that have poor defenses anyhow, so just hit then before they hit you first, since the Focus Sash affords you a free turn. His 4th moveslot is really up to personal preference. I opted for Aerial Ace so I would have a move that never misses, and to hit pesky Grass types like Shiftry and Meganium. However, that super effective Aerial Ace is not as strong as a one-type resisted Crabhammer or Night Slash, so you may prefer something with more power. Superpower could fill that void, but remember it lowers Attack and Defense 1 stage each. There are other options, but these are the better ones in my opinion.
 
How do you get this bully of a Pokemon?

(1) Breed a female DW Corphish with a male Feraligatr that knows Dragon Dance (an Egg Move) and Superpower if you want that (level up, or you can use a B2W2 move tutor for it later). If you don't want Superpower, you can use a Horsea for breeding, as it learns Dragon Dance through level up.
(2) Aim for a Jolly Nature. Teach it Aerial Ace via the respective TM if desired.

I'll have a video of this beast up shortly, he is just ferocious.

Brock out.