Their skill level would be on par with Sand Sprites or Rock Trolls.

Their skin would be a mottled mix of greens and tans.

They would either attack from range with a bow (A forest goblin archer steps out from behind a massive tree and begins aiming at you)

Or they would drop out of trees and attack at melee (A forest goblin tracker drops down from a tree and advances towards you).

On a rare occasion, a Forest Goblin Tracker would appear, he would use Life mana spells to debilitate and then cast a goblin only spell that causes vines and branches to attack.

They would be skinable for hides, parts, and bones, and would carry boxes, coins, gems, etc.

I could see them being in an area next to Leth near the nyads and dryads.

__
"Technically correct" is the worst kind of correct.