Shapeshifting fiction

Shapeshifting or transformation fiction is a genre in fiction which deals with physical transformation, usually called shapeshifting. Some of the more popular themes include werewolves, vampires, and age regression. In a broader sense the term includes stories about characters who shrink or grow in size without changing their form.

Transformation in this regard is physical, as opposed to mental or personality, since in many fictions, even with no fantastic element, a character develops, transforms or changes, throughout the story.