Updated.
Suggestions for the attack line? Apparently, they only fight with weapons, and then only do so at Large or Huge size. If we give it a weapon, then it will scale with the leshy, defeating the need for the tree club. Just list unarmed strikes?
I'd prefer the Leshy's gear doesn't scale with it, since IIRC it doesn't in the myths. (If you're wondering why they don't rip out of their clothes, from what I remember of Russian folklore there isn't much mention of them wearing garments, although I remember one story of one wearing a cloak of living leaves, I don't think it was an authentic folktale).
Besides, I like the idea of the 4 foot tall hairy elf the PCs are talking to getting angry, shooting up to 30 feet tall and uprooting a nearby pinetree in a menacing fashion.
Anyhow, weapons are a bit complicated, since they'll vary by size - maybe give them representative entries for Tiny, Medium and Huge?
DR 10/cold iron I guess. They'd be pretty squishy otherwise.
Skills: 10 at 11 ranks
Concentration, Diplomacy, Hide, Intimidate, Knowledge (nature), Listen, Move Silently, Spellcraft, Spot, Survival?
Feats: 3
Those skills look fine to me.
As for feats, the definitely need something to boost that Fort save, so Great Fortitude for a start. Actually, I'd also suggest upping their Con, since 12 seem way too low. Maybe 18 or 20, to be on a par with its other stats?
We could give it a weapon-enhancing feat. If we give it a quarterstaff, maybe Two-Weapon Fighting, or if we opt for greatclub perhaps Power Attack. Although with its low attack bonus it might not get much return for it.
Combat Reflexes probably offers more bang for the buck, for when it Hulks up to Huge size and gets extra reach.
