Slaking (M) @ Leftovers/Life Orb
EVs: 252 Atk / 252 Spd / 4 SDef
Adamant Nature (+Atk, -SAtk)
- Shadow Claw
Okay, this set has a very particular strategy in mind. It needs a lot of preparation and luck to pull off successfully. As we all know, Slaking has fantastic stats, but is crippled by his ability, forcing him to do nothing every other turn. However, Gen V introduced a new Ghost type, Cofagrigus, with the unique ability Mummy. When a pokemon makes a contact move against him, their ability becomes Mummy too. The ability can spread from pokemon to pokemon through physical contact.
Here's the good part. You send out Cofagrigus on an opponent's physical attacker, who then attacks and gains Mummy. You then send out Slaking. Even if the opponent catches on to your plan and tries to switch out, you use Pursuit, guaranteeing that you will lose your ability. Now, with no Truant, you are free to completely destroy the opponent's team.
Pursuit is there for obvious reasons. Return is your main STAB move, with its 153 base power, sure to leave a dent in anything that doesn't resist it. Earthquake covers Rock- and Steel-types trying to wall you, while Shadow Claw hits Ghost types super effectively, rounding off your coverage. This strategy doesn't always work, but if it does, it's GG no re. Hope I helped :]