Hmm, makes a nice physical wall in UU and RU.
Alomomola (F) @Leftovers/@Damp Rock
EVs: 252 HP / 196 Def / 60 Sp. Atk
Bold Nature (+Def, -Atk)
Alright, I got this set from a friend, but he doesn't have an account here, so I'm posting for him.
The basic strategy is to start off with Rain Dance. Leftovers are usually better, but Damp Rock gives you a full 8 turns of rain, which most of the time works in your favor (unless they use Thunder.. but then again, why are you using a physical set against a special Pokemon?)
After Rain Dance, if you're trying to stall them out, go Toxic first . This usually works if they're a Fire Pokemon, because Rain Dance neutralizes their STAB, and they're immune to the burn from Scald.
For all the other Physical pokemon, after Rain Dance, spam Scald. Eventually it will get the burn, which will help you survive hits even more.
And then, after everything is well and done, heal it off with a nice nap. Hydration will cure you of your sleep, unless the rain ends at the end of the turn you Rest.