Medusa

Medusa is a Hardmode enemy rarely found near Marble Caves. Ordinarily a relatively fast-moving melee attacker, Medusa has the ability to inflict the Stoned debuff through her gaze. The debuff's onset is marked by Medusa's snake hair lashing out red tongues, as well as a unique noise and particle effect, giving players notice before they are petrified. Players facing Medusa when the animation completes will be turned into stone, completely immobilizing them until the effect wears off. Solid blocks between the player and Medusa can prevent the gaze from inflicting the Stoned debuff, as can simply facing the other direction before the effect is complete.

Tips

 * Facing away from Medusa while fighting off other enemies is recommended.
 * Yoyos, the Magic Missile, and the Flying Knife make great weapons against Medusa as you can use them behind you, and around corners, out of her line of sight. White String also helps if you decide to use yoyos.
 * Ironically, the Medusa Head is also a great weapon against Medusa as you can use its "stare" while looking the other way.
 * The combo of removing fall damage protection and increased fall damage taken can instantly kill even the strongest players.
 * Using the Feather Fall Potion can still protect you from taking fall damage, even when you are stoned.

Trivia

 * Medusa is the name of the most well-known of the Gorgons of Greek mythology: a species of creatures who look like women, have living serpents for hair, and cause humans who look at them to turn into stone. According to Greek mythology, Medusa was turned into a gorgon by the goddess Athena.
 * The word "marble" is of Greek origin, as is "Medusa" and "hoplite" (which means "soldier/infantryman"). In Terraria, Medusa and Hoplites both spawn in Marble Caves.

History
Médusa 메두사