He escaped from AMMA’s cosmic egg and filched the whole yolk. Not because he was hungry, but because he thought his twin sister YASIGI was hiding inside. She wasn’t; AMMA had placed her in the care of the NOMMO Twins.
Frustrated YURUGU was left with egg on his face and a whopping big wobbly yolk to deal with. He decided to mate with it. But the yolk became hard-boiled and turned into a dry, dusty yellow Earth.
To save the world from YURUGU’s incestuous behavior, which was threatening the entire fabric of creation, AMMA sacrificed one of the NOMMOs and scattered the bits all over the universe. YURUGU slinked away and might now be ruling the dry Dogon wastes disguised as a pale fox. See OGO.