A werecat (also written in a hyphenated form as were-cat) is an analog to "werewolf" for a feline therianthropic creature.

Ailuranthropy comes from the Greek root words ailouros meaning "cat", and anthropos, meaning "human" and refers to human/feline transformations, or to other beings that combine feline and human characteristics. Its root word ailouros is also used in ailurophilia, the most common term for a deep love of cats.

Ailuranthrope is a lesser-known term that refers to a feline therianthrope.

Depending on the story in question, the species involved can be a domestic cat, a tiger, a lion, a leopard, a lynx, or any other type, including some that are purely mythical felines. Werecats are increasingly featured in popular culture, although not as often as werewolves.

European folklore usually depicts werecats as people who transform into domestic cats. Some European werecats became giant domestic cats or panthers. They are generally labelled witches, even though they may have no magical ability other than self-transformation. During the witch trials^[which?], all shapeshifters, including werewolves, were considered witches whether they were male or female.

African legends describe werelions, werepanthers or wereleopards. In the case of leopards, this is often because the creature is really a leopard deity masquerading as a human. When these gods mate with humans, offspring can be produced, and these children sometimes grow up to be shapeshifters; those who do not transform may instead have other powers. In reference to werecats who turn into lions, the ability is often associated with royalty. Such a being may have been a king or queen in a former life.

In Africa, there are folk tales that speak of the "Nunda," or the "Mngwa," a big cat of immense size that stalks villages at night. Many of these tales say it is more ferocious than a lion and more agile than a leopard. The Nunda are believed by some to be a variation of therianthrope that, by day, is a human, but by night becomes the werecat. No actual evidence of such a creature existing has ever been documented, but in 1938, a British administrator named William Hitchens, working in Tanzania, was told by locals that a monstrous cat had been attacking people at night. Huge paw prints were found to be much larger than any known big-cat, but Hitchens dismissed the case, believing it more likely to be a lion with gigantism.

Mainland Asian werecats usually become tigers. In India, the weretiger is often a dangerous sorcerer, portrayed as a menace to livestock, who might at any time turn to man-eating. These tales travelled through the rest of India and into Persia through travellers who encountered the royal Bengal tigers of India and then further west. Chinese legends often describe weretigers as the victims of either a hereditary curse or a vindictive ghost. Alternatively, the ghosts of people who had been killed by tigers could become a malevolent supernatural being known as "Chang" (伥), devoting all their energy to making sure that tigers killed more humans. Some of these ghosts were responsible for transforming ordinary humans into man-eating weretigers. Also, in Japanese folklore there are creatures called bakeneko that are similar to kitsune (fox spirits) and bake-danuki (Japanese raccoon dog spirits).