Dark Guardian is believed to be the protector of the lost minis.
It is believed the minis trust him to find a good owner for the eggs they cannot take care off.
Dark Guardian will ask you for 3 items. Most of them are books, but he may also ask for a toy or food.
After bringing the required items, he will ask you a question from one of the Pet- and HealthPedias.
If the question has been answered correctly, he will reward you with one of the puzzle pieces below.
This quest can be done every 360 minutes after completing.
If you have all 12 different pieces of the Evolutions Puzzle, you can take it to the Riksja Driver.
More information about the Riksja Driver can be found here.