|La Calchona (courtesy Austin Whittall)|
She was a witch. She obtained certain ointments with a view to turning herself into a sheep. She would go out in the night to do this. Her husband realized she was making nocturnal excursions and wondered why. He determined to follow her.
On doing so, he saw her apply the ointment and become a sheep. This, he felt, had to stop. He returned home and destroyed the rest of the ointment. La calchona had to remain in animal form forever.