"If a tree branch shakes when there is no wind, it's a SUDOWOODO, not a tree. It hides from the rain." ~ Crystal
"It stands along paths pretending to be a tree. If it starts raining, it seems to disappear."
Nature: Sassy or Brave
Item: Custap Berry / Assault Vest
EVs: 240Atk/ 50 Def/ 220 SpDef
Flail / Sucker Punch
Block / Rock Tomb
Stealth Rock/ Stone Edge
Does anybody remember the dancing tree of Goldenrod City? It was a strange encounter with a dancing tree that turned out to be a Sudowoodo. Ive always liked Sudowoodo's strange design. Let's talk about it. Sudowoodo is held back by its Speed and Special stats, but it makes up for these by being rather Defensive. It also has Sturdy, which will prevent OHKOs with 1 HP. By using Custap Berry, you gain priority on your next move when in a pinch. Flail is powered up to BP 200 when Sudowoodo is in this state. It doesn't guarantee OHKO or 2HKO, but it does provide neutral coverage and benefits from Ability. Block is used to trap physical attackers. When possible, Sudowoodo should be matching up to phys attackers so it can make use of its best move: Counter. Sturdy prevents OHKO from Fighting or Ground type moves, and it will Counter for 2x damage. Lastly, Stealth Rock rounds out the set, which means that you can either open with S. Rock or close with it after eating a Custap Berry.
Another set I thought was decent was the Assault Vest set, which gives Sudowoodo survivability to Special moves at the cost of favored Status moves. Counter remains a staple on the set, while Rock Tomb fills the space for Block, Stone Edge replaces Stealth Rock. Flail could still be usable on this set, however, Sucker Punch will give Sudowoodo much needed priority in place of Custap Berry.
Obviously, Special Attackers, especially Water types, frighten Sudowoodo out, but overall, Sudowoodo has an interesting place on any Defensive team looking for a wild card like the Imitation Pokemon.