What creature did Perseus slay?

Perseus slew Medusa, the snake-haired Gorgon whose gaze could turn living beings to stone.

In Greek myth, Medusa was once a beautiful woman transformed into a monster. Perseus was sent to bring back her head, a seemingly impossible task. The gods aided him: Athena gave him a polished shield, Hermes supplied a sword, and other divine gifts helped him approach the Gorgons safely. Perseus used the shield’s reflection rather than looking directly at Medusa, then decapitated her while she slept.

Medusa’s severed head remained dangerous and became a weapon. Perseus used it against enemies, including the sea monster threatening Andromeda, before giving the head to Athena, who placed it on her protective aegis. A common mix-up is confusing Medusa with the Hydra or Chimaera, which were different monsters defeated by Heracles and Bellerophon. Medusa’s death also produced Pegasus and Chrysaor, her children by Poseidon.