The Count Lucanor (UP)

In order to be able to get this trophy, you will need to open the treasure chest in the garden (Lucrezia's toy).

Once you've fed the worm from the depths (Delicious), it will turn into a butterfly. Follow it back into the main depths area. Eventually it will land on a skeleton. Pick up the butterfly to unlock this trophy. You don't need to pick it up with the butterfly net equipped but it needs to be in your inventory. Having this butterfly in your inventory is required for several of the ending trophies.