Narasimha, the man-lion, is the fourth avatar of Vishnu, and his story is a masterpiece of the logic of loopholes. The demon-king Hiranyakashipu has won a boon that he can be killed by neither man nor beast, neither indoors nor out, neither by day nor night, neither on the ground nor in the air, and by no weapon, a boon that seems to make him invulnerable. Vishnu defeats it on every term at once: he appears as a being who is neither man nor lion but both, at dusk (neither day nor night), on a threshold (neither indoors nor out), takes the demon onto his lap (neither ground nor air), and tears him open with his claws (no weapon). The precision with which each condition is answered is the point of the tale.
The man-lion has a long visual history. Identifiable Narasimha images appear already in Gupta period art of the fourth to sixth centuries CE, among the earliest surviving anthropomorphic-theriomorphic depictions of a Vishnu avatar, well before the narrative's elaboration in the Puranas reached its classical form, indicating that the god's iconography and his myth of loophole-defeating violence developed together over a long span rather than the image simply illustrating an already-fixed story.