Jailor Trophy in Yoku's Island Express
Complete Thorn quest
How to unlock Jailor
This quest becomes available after falling through the thorns in the drain of the pinball tables a certain cumulative number of times - I believe that this is 50, and you'll see a brief cutscene with a counter as you reach various thresholds. Once you reach this total, go to the area below the village where different colour styles can be applied to the ball (see A ball for every occasion above) and apply the Crimson Sprinkle, giving a red ball. Now, you need to find the area seen in the cutscene, which is hidden to the bottom-right of the waterfall below the village. Here, you'll be given a quest to complete, the completion of which will earn this trophy, as well as the Boon of Plenty upgrade.
THIS VIDEO from YouTube user Sucha Gra demonstrates this quest (ignore the first three minutes).