One possible story could be that a woman, who has always felt a deep connection to nature, discovers an ancient spell in a hidden book. As she reads the incantation, she starts to transform into a deer. She then experiences the forest from a new perspective, running freely among the trees and making new animal friends.
In a 'woman to animal tf story', if the woman becomes a fox, her social life will be very different. She'll be more solitary, except during mating season. She'll have to rely on her hunting skills to survive. She can't just go to the grocery store anymore. Also, she'll need to be constantly aware of predators, like wolves or large birds of prey. She'll have to use her speed and cunning to stay alive. Her whole world will revolve around the forest and its rhythms.
One well - known story is 'Beauty and the Beast' where Belle has a transformation of sorts in the sense that she comes to live among the enchanted objects and the Beast, who is part - animal. Another could be the story of Circe in Greek mythology, who turned many men into animals, and there could be stories where a woman is cursed to transform into an animal like a swan as in some folktales.
The main distinction of porn with a story genre from regular porn is the presence of a coherent narrative. Regular porn often jumps straight to the sexual action, while the story genre tries to add some kind of story framework around it. But in the end, both are adult-oriented and feature explicit sexual content.