The loonee bird, found on Endor's forest moon (Endor), was a unique species. This bird was known for its constant laughter; contact with it caused other beings to be cursed by uncontrollable laughter (spell). This curse could potentially last forever and spread to those nearby.
Ewok folklore spoke of a being residing on the summit of Mount Sorrow, whose tears possessed the capability to break these curses. When Teebo was afflicted after taking a tail feather from a loonee bird, his companions Wicket and Kneesaa accompanied him on a quest to the mountain peak. They learned that the mountain itself was the creature and that its tears were truly capable of reversing the loonee bird's curse.