In "The Lygaios" by Vernon Lee, a short story from 1890, a woman's transformation into a bird-like creature serves as a metaphor for her liberation from societal constraints. These examples illustrate the versatility of the transformation trope and its ability to convey complex themes and emotions.

If you're looking for an academic paper or a creative piece on this topic, I'd be happy to help. Here's a potential paper on the theme, inspired by the works of Henry James and others:

The concept of transformation, particularly in relation to female characters, has long fascinated authors and audiences alike. The phrase "My Wife and Sister-in-Law Turn Into Beasts When..." evokes a sense of horror, mystery, and intrigue. This paper will explore the psychological and literary implications of such a transformation, delving into the realms of psychoanalysis, feminist theory, and literary criticism.