First time making a moveset, so… hope this is good.
Applin @ Oran Berry
EVs: (116 Def / 196 SpDef / 196 HP) OR (116 HP / 196 Attack / 196 Speed)
Impish Nature OR Adamant Nature
- Defense Curl
- Grassy Glide
- Recycle / Sucker Punch
This set is more or less built around the Defense Curl-Rollout sweep strategy. Doing this with an Applin might be a bit difficult, but it's more for the gimmick than anything else. So, obviously, you start off with Defense Curl to boost your limited stats, and also to give Rollout a much-needed damage boost. Rollout also provides some coverage against scary Ice- or Flying-types if you can't switch. Oran Berry is in case you take damage, with Ripen for extra recovery. You can Recycle it if needed, or Sucker Punch to get in a quick hit. Grassy Glide is for STAB, plus, it's got priority under Grassy Terrain. As for EVs, the first set is for a more tanky build. The second is more for sweeping, if you can sweep with a worm in some fruit. Since all of Applin's moves are Physical, you don't need a Special Attack-boosting nature. Impish is for some extra tankiness, while Adamant boosts Applin's limited Attack.
Hope this was helpful! If you have any suggestions or revisions, let me know.