Mossy Rocks is the tenth puzzle in Virtual Villagers 4.
The requirement to solve: Puzzle 12.
Have an adult catch a fish. This will make a crab appear on the beach to the right of the cliff staircase.
Very quickly pick up a child and drop it on the crab. Repeat again with another child.
Now drag an adult to the crab and they will pick up the crab and take it to the mossy rocks at the base of the pond.
You need to do this process five times.