Uthaitaewee

In the underwater kingdom ruled by the Great Naga King, there lived his royal daughter, Samut Mala. One day, Samut Mala fled the underworld to visit the human realm, where she fell in love with a Rukkha Devada (a tree spirit) dwelling in a tree by a pond.
When the tree spirit was punished by Lord Indra and exiled beyond the Himavanta Forest, Samut Mala, who had become pregnant, waited until she laid an egg. She wrapped the egg in her breast cloth (Sabai) and sprayed it with venom for protection before returning to the underworld.
By chance, a toad attempted to eat the egg but died from the Naga's venom. When the egg hatched into a baby girl, the child believed the toad was her mother and lived inside its skin. An elderly couple passing by while fishing rescued her and raised her as their own, naming her Uthai Devi.
As Uthai Devi grew into a beautiful woman, she met Prince Sutharaj. To win her hand, the elderly couple set a condition: the Prince had to build a golden bridge stretching from the palace all the way to their home. Prince Sutharaj succeeded, and they were finally married.
However, the Prince was later forced to marry Princess Chanthana due to a prior vow. Princess Chanthana plotted to eliminate Uthai Devi, but her schemes failed, and Uthai Devi remained safe. In the end, Uthai Devi and the Prince lived together in lasting happiness.