In Greek mythology, the Gorgons traditionally had snakes instead of ordinary hair.
The snake-haired image is especially associated with Medusa and became one of the defining features of her appearance in later Greek and Roman art. Ovid’s Metamorphoses gives a famous Roman literary version in which Medusa’s hair is transformed into snakes by Minerva, the Roman equivalent of Athena.
Earlier Greek representations can vary. Archaic Gorgons may appear as frightening winged creatures with large eyes, tusks, protruding tongues, and animal-like features. The fully familiar image of a beautiful woman with living snakes for hair became increasingly influential over time.
The snakes are not the same feature as the petrifying gaze. In myth, Medusa’s gaze turns onlookers to stone, while the serpents identify her as a monstrous Gorgon. Those two traits are often combined in modern depictions.