Ars Magica: Druesberg
Fifty years ago, the five-year-old Gemaric was transformed into a rock in order to protect him during the Sundering of Calebais. He later developed the ability to move around on tiny human-like legs, and has a basic ability to perceive the world around him.
The magi found him there and promised his mother’s ghost that they would take care of him. True to their word, they took him back to the covenant, where he now appears to be happy. He appears to enjoy startling Arcturus’s magical dogs, who do not know what to make of him.