Shapeshifting is the ability to change one's physical form or appearance, transforming from one shape into another. In myths and stories from cultures around the world, shapeshifters might change from human to animal, from one creature to another, or even from solid to liquid. Greek gods transformed into swans and bulls, Norse trickster Loki could become a salmon or a fly, and werewolves shift between human and wolf forms under the full moon.

In modern stories, shapeshifting often comes with rules: some characters can only hold a form for a limited time, others feel pain during the transformation, and some can only shift into specific creatures. The X-Men's Mystique can mimic any person perfectly, while animagi in fantasy stories might master just one animal form after years of practice.

The word can also describe someone who adapts their behavior or personality to fit different situations, though this usage suggests something slightly deceptive. Someone might say a politician is shapeshifting when they change their message depending on their audience, or that a chameleon-like student acts completely different around teachers than around friends. This metaphorical meaning captures both adaptability and a certain slipperiness, the sense that you never quite know who someone really is underneath all those transformations.