The creature in Greek mythology known for having snakes for hair is Medusa. One of the Gorgon sisters, she was transformed into a monster as punishment by the goddess Athena. Medusa's gaze could turn anyone who looked at her into stone, making her a feared figure in mythology. Her story often reflects themes of beauty and monstrosity, as she was once a beautiful maiden before her transformation. Ultimately, she was slain by the hero Perseus, who used her severed head as a weapon.