Petrifaction in mythology and fiction

In Greek mythology, Medusa (/mɪˈdjuːzə, -sə/; Ancient Greek: Μέδουσα, romanized: Médousa, lit. 'guardian, protectress'), also called Gorgo (Ancient Greek: Γοργώ) or the Gorgon, was one of the three Gorgons. Medusa is generally described as a woman with living snakes in place of hair; her appearance was so hideous that anyone who looked upon her was turned to stone. Medusa and her Gorgon sisters Euryale and Stheno were usually described as daughters of Phorcys and Ceto; of the three, only Medusa was mortal.

Medusa was beheaded by the Greek hero Perseus, who then used her head, which retained its ability to turn onlookers to stone, as a weapon until he gave it to the goddess Athena to place on her shield. In classical antiquity, the image of the head of Medusa appeared in the evil-averting device known as the Gorgoneion.

In Greek mythology, Andromeda (/ænˈdrɒmɪdə/; Ancient Greek: Ἀνδρομέδα, romanized: Androméda or Ἀνδρομέδη, Andromédē) is the daughter of Cepheus, the king of Aethiopia, and his wife, Cassiopeia. When Cassiopeia boasts that she (or Andromeda) is more beautiful than the Nereids, Poseidon sends the sea monster Cetus to ravage the coast of Aethiopia as divine punishment. Queen Cassiopeia understands that chaining Andromeda to a rock as a human sacrifice is what will appease Poseidon. Perseus finds her as he is coming back from his quest to decapitate Medusa, and brings her back to Greece to marry her and let her reign as his queen. With the head of Medusa, Perseus petrifies Cetus to stop it from terrorizing the coast any longer.

As a subject, Andromeda has been popular in art since classical antiquity; rescued by a Greek hero, Andromeda's narration is considered the forerunner to the "princess and dragon" motif. From the Renaissance, interest revived in the original story, typically as derived from Ovid's Metamorphoses. The story has appeared many times in such diverse media as plays, poetry, novels, operas, classical and popular music, film, and paintings. A significant part of the northern sky contains several constellations named after the story's figures; in particular, the constellation Andromeda is named after her.

Decapitation is the total separation of the head from the body. Such an injury is invariably fatal to humans and all vertebrate animals, since it deprives the brain of oxygenated blood by way of severing the jugular vein and common carotid artery, while all other organs are deprived of the involuntary functions that are needed for the body to function.The term beheading refers to the act of deliberately decapitating a person, either as a means of murder or as an execution; it may be performed with an axe, sword, or knife, or by mechanical means such as a guillotine. An executioner who carries out executions by beheading is sometimes called a headsman. Accidental decapitation can be the result of an explosion, a car or industrial accident, improperly administered execution by hanging or other violent injury. The national laws of Saudi Arabia and Yemen permit beheading. Under Sharia, which exclusively applies to Muslims, beheading is also a legal punishment in Zamfara State, Nigeria. In practice, Saudi Arabia is the only country that continues to behead its offenders regularly as a punishment for capital crimes. Cases of decapitation by suicidal hanging, suicide by train decapitation and by guillotine are known.

Less commonly, decapitation can also refer to the removal of the head from a body that is already dead. This might be done to take the head as a trophy, as a secondary stage of an execution by hanging, for public display, to make the deceased more difficult to identify, for cryonics, or for other, more esoteric reasons.