Crawdaunt, most famous for its ability in the Hax Tower, sweeping teams without a Sturdy Pokemon, a Ghost, or a Focus Sash Pokemon. After that, it is best known for being inferior to its older Crab brother, Kingler, with its superior stats. However, all is not lost as Crawdaunt does have STAB on Dark type moves, oh wait, so does Sharpedo, who has equal or better sweeping stats. Ironically enough, it's the fact that it is little brother to both Kingler and Sharpedo that gives it the advantage. Older brother Kingler taught it how to break bricks and take really weak hits, something other older brother Sharpedo can only dream of. Other older brother Sharpedo taught Crawdaunt how to Crunch on things and slash them in the nights, and get STAB on both, and attack from both sides, something Kingler cannot do. 

Crawdaunt@Life Orb
Naughty-136 Atk /124 Spd /248 SpAtk
Hyper Cutter
- Crunch
- Surf
- Brick Break
-

This set is to be used in OU to break the common walls that switch into it. It outspeeds minimum base 70s allowing it to beat most walls other than Cresselia and Gliscor, who may be afraid of switching into a STAB water attack.

Taunt is an option in the last slot for stopping status and healing. Another option is Ice Beam to hurt Tangrowth, and dragons being able to OHKO Yache-less Garchomps and Salamence by association. HP Elec/Grass can be used for Gyarados or Swampert respectively, but don't expect it to do much against most other bulky waters such as Suicune. Toxic is another option against bulky waters. Superpower is an option over Brick Break, but you do have to switch out. Knock Off can be used as a disruptive move, but at the cost of 10% of its own health, making it not recommended. Swords Dance is an option better left to Kingler.

Brick Break Vs Blissey
341 Atk vs 130 Def & 688 HP (75 base power): 368 - 434 (53.49% - 63.08%) | Multipliers: 1.3 * 2

Crunch Vs Cresselia
341 Atk vs 333 Def & 444 HP (80 base power): 230 - 272 (51.8% - 61.26%) | Multipliers: 1.3 * 2 * 1.5

Crunch Vs Dusknoir
341 Atk vs 405 Def & 294 HP (80 base power): 188 - 224 (63.95% - 76.19%) | Multipliers: 1.3 * 2 * 1.5

Surf Vs Hippowdon
278 Atk vs 223 Def & 420 HP (95 base power): 332 - 392 (79.05% - 93.33%) | Multipliers: 1.3 * 2 * 1.5

Surf Vs Forretress
278 Atk vs 196 Def & 354 HP (95 base power): 189 - 223 (53.39% - 62.99%) | Multipliers: 1.3 * 1.5

Surf Vs Weezing/Skarmory
278 Atk vs 176 Def & 334 HP (95 base power): 211 - 249 (63.17% - 74.55%) | Multipliers: 1.3 * 1.5

Surf Vs Magnezone
278 Atk vs 216 Def & 324 HP (95 base power): 171 - 202 (52.78% - 62.35%) | Multipliers: 1.3 * 1.5

All damage calculations were done with the bulkiest EV spreads that would be likely used. As you can see, Crawdaunt can 2HKO many likely switch-ins. It does however, have problems with bulky waters, only getting 3-4HKOs on Suicune and Swampert. HP Grass does 2HKO Swampert, but still has problems against Suicune. HP Electric has a 92% chance of OHKOing Gyarados with SR support.

Thoughts and suggestions?

It's still way to slow to ever be an option in OU battling.

Yeah, I agree. Seriously, the amount of UUs that can be potent in OU is pretty low, and many of them don't have any business in UU to begin with *coughclefablecoughninetales*.

Outspeeding base 70's is all it needs to do as the only walls that this can be that outspeeds this are Gliscor and Cresselia.

so this is some sort of wall breaker? nido does it better and he's way too slow as any common sweeper eats it