Pyukumuku @ Leftovers or Heavy Duty Boots
Ability: Unaware  
EVs: 252 HP / 252 Def / 4 SpD or 252 HP / 4 Def / 252 SpD
Bold or Calm Nature  
IVs: 0 Atk  
- Recover  
- Toxic  
- Rest / Block  
- Soak / Spite

Other options: Counter, Mirror Coat, Protect