The Korok Who Cried Monster
The quest is unlocked after completing The Future of Hyrule scenario.
"A Korok is feeling down. They saw a huuuge monster—as big as the Great Deku Tree!—but none of their siblings will believe them. Show the doubters proof of the massive beast's existence."
"After the Korok showed off parts from the giant monsters, no one doubted their story anymore. The Korok celebrated by playing games with you under the silent gaze of the Great Deku Tree."
- Hestu: Enhanced Ability