Spiderwick Chronicles

While on Chapter 3 you'll have to go down the cellar, then get 3 spirits to open the rock door.

As you enter the caves, you'll find a Will o the Wisp (catch him), then go left and release the Wisp as you find the goblins, they'll jump to the void trying to catch the faerie.

Poor poor goblins...

You can get this on Chapter 2, when you enter the Quarry. Go up the path on the left, It will lead you onto a narrow path along the rocks. One goblin will attack you, release the Wisp (Will O' The Wisp) as you see the goblin, and he should walk right off the ledge.
Achievement Unlocked!