Camerupt

Camerupt @ (insert color here) Scarf
Nature: Relaxed, Lax, Gentle, Sassy, Lonely, Brave, Naughty

- Lava Plume
- Rock Tomb
- Earth Power / Earthquake
- Rock Slide / Rock Polish / Howl

There are a lot of options with this one. Open up with Lava Plume to get your four hearts to start. Then use the 3rd slot move if you end up last, or Rock Tomb if you don't end up last. If you used your 3rd slot move, then use whichever 4th slot move you chose. Then decide on what move to use in the last appeal based on where you are in line. If you're first, Lava Plume. If you're last, Earth Power or Earthquake. If you're somewhere else, then make your decision on what you'd like to use based on what gives the most hearts.

As for all the decisions involved, it depends on what you want to aim for in contests and in battle. Choose your nature depending on what contest you're looking for and what stat you feel you can afford to take a loss in. The decision between Earth Power and Earthquake depends on if you want a physical or special move and if you're willing to sacrifice 10 base power in the case of Earth Power. Also, the decision depends on if you want to have a mixed contest Camerupt or you're using it only for Tough contests. If the former, then Earth Power adds a smart move to your set. If the latter, than Earthquake works just fine.

The fourth slot just depends on personal preference. Rock Slide is a tough move that just gives 3 hearts. Rock Polish is another tough move, but it ensures you go first in the next turn, which can be helpful since you're using Lava Plume. Note that if you use Rock Polish, I'd recommend Earth Power just to add some diversity and allow your Camerupt to participate in other contest types. The final option is an egg move, but I really think that it's the best choice. Howl allows you to double your score in the next turn, and is likely to put you up front as well, which would give you 8 hearts in the next appeal.

Finally, the battling aspect of this Camerupt. If you choose Howl as your fourth slot move, I'd use Earthquake in the second slot, so that you have two moves that can be boosted by Howl. If you're wary of using Rock Tomb because of the accuracy, you could use Ancientpower as an alternative. It does the same thing in contests, and of course there's a 10% chance of boosting all stats, which never hurts. This of course means that you now have 2 special moves and 1 physical move, so choose your nature and EVs accordingly. Lava Plume can be replaced by a number of attacks, including Flamethrower, Fire Blast, and Heat Wave. Pick your poison, personally I like the burn rate of Lava Plume.

As for an EV spread, I'd personally use 252 in Attack or Special Attack, depending on your moves, and then 126 in the other attacking stat and 126 in either Speed or whatever stat your nature increases(assuming it's not attack). It's again left to personal preference.