After learning Faron’s part of the Song of the Hero and draining the Faron Woods, talk to Instructor Owlan. When you enter his room, it is obvious that he enjoys collecting plants. In fact, he has run out of plants to study. He asks you to find a new, exotic plant that he has never seen before. Once Fi sets her dowsing ability to find such a plant, fly over to the Faron Province and descend by the Viewing Platform.
Dowse to find Oolo, a Kikwi, east of the Great Tree. He is tired of hiding from monsters and wants a safer place to live. Tell him that you know where he can go, and call Scrapper. Ascend to the sky, then return to Owlan’s room. Owlan is so excited after seeing Oolo, a combination of a plant and an animal, that he produces 5 Gratitude Crystals for you.