A young Aboriginal woman, Naruni, was promised to a tribal elder.  But she was attracted to a younger man, Kuralka, so they both ran away for many months.  They finally returned to the tribe in disgrace.  They were both punished by the elders and Naruni was turned into a duck and Kuralka was changed into a giant water-rat.  Both were banished to a far distant river.

Turned away by her people, Naruni hatched two eggs.  When the eggs hatched they did not contain ducklings but strange creatures with bodies of fur, webbed feet and duck bills.

Naruni's disappointment was so strong and with her yearning for solid ground plus her loss of tribal life, she eventually died.  But her two children thrived in their watery home and established the platypus family.