Battle Moveset

A Good Moveset for Loudred would have to be this:

Attacks:

Return
Shadow Ball
Brick Break
Overheat

Items Attached:

Liechi Berry
Preferred Nature:

Adamant

Strategy Using Loudred

Loudred isn't a pokemon to boast about since its stats aren't that good. Although it does have alright HP, his defenses are poor and won't take a hit from the much stronger, fully evolved pokemon.
Exploud can do things much better than Loudred can, so this is basically given it powerful moves and a STAB move too, after all, it will need that boost in strength.
Loudred has a weakness to fighting types, so one brick break from a powerful physical sweeper would cause this pokemon to faint. But, Loudred's attack and special attack are equal in strength. Overheat isn't such a bad move either since that relies on special attack and the other moves don't, so the special attack loss from overheat will not effect the other moves.
EV's into Attack for the boost it needs in that stat, trying to boost Loudred's speed could be considered a waste since even with a boost it won't be that fast. At least with defense/special defense, it does stand a slim chance of surviving a hit.
Shadow ball covers those ghost pokemon that return or brick break won't hit. So, because of Loudred's low attack, this moveset goes for full on power.
Overall, Loudred isn't that good of a pokemon, as its evolution, Exploud can do the above moveset much more effectively along with a few others.

EV Corner:

Max out the EVs in Attack for Loudred with any remaining in Defense & Special Defense

Strategy Against Loudred

Loudred's Defense's are equal so if you hit with Fighting type moves it'll be down in no time

Contest Moveset

A good Contest Moveset for Loudred would have to be this for the Cute Contest best with Timid, Hasty, Jolly or Naive Nature:

Attacks:

Rest
Snore
Sleep Talk
Attract

Items Attached:

Pink Scarf

Strategy Using Loudred

If you do the attacks in this following order you should have very few problems; 1st - Rest, 2nd - Snore, 3rd - Rest, 4th - Sleep talk/Snore, 5th - Attract

Locations in Games

Ruby/Sapphire Victory Road Colosseum Trade from R/S Fire Red/Leaf Green Trade from R/S

Animé Appearences

Loudred has had a few Anime Appearences. Most of the time, it was a Loudred on Dewford Island that kept being awoken by Team Rocket and caused trouble. After that, Ash's Treecko was battling with a semi-disobediant one until they both evolved Episode 298: A Hole Lotta Trouble! Episode 299: Gone Corphishin`! Episode 302: Turning Over A Nuzleaf! Episode 303: A Three Team Scheme! Short 6: Gotta Dance! Episode 336: Skitty & Delcatty! Enter the Legendary Co-ordinator! Episode 342: Critical Situation! Exploud VS Grovyle!