Medusa, one of the three gorgons of Greek Mythology. Like her gorgon sisters, Euryale and Stheno, Medusa was a hideous fanged monster. One glance upon a gorgon would turn the onlooker into stone. Medusa also had wings (in most depictions), and hair made of snakes.
Unlike her sisters, Medusa was a mortal creature. She was ultimately killed by Perseus, who cut off her head. He was able to slay her by looking only at her reflection in a mirrored shield. He presented her head to the goddess Athena. Athena then took the head, which still possessed its petrification ability, and mounted it on her shield (or cloak, in some accounts).
Medusa, and probably her sisters, were worshipped in early Greek religion, and perhaps even earlier, as protective creatures. Medusa became very popular in ancient Greek art, and her image was often placed in homes and on armor and tombstones in hopes of protecting the bearer. Medusa's head was said to ultimately be buried under the agora at Argos.
Medusa painted on a wooden shield
by Caravaggio, circa 1592–1600 CE.