This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Gorgon (Greek)
A Gorgon is a creature in Greek mythology. Gorgons occur in the earliest examples of Greek literature. While descriptions of Gorgons vary, the term most commonly refers to three sisters who are described as having hair made of living, venomous snakes and horrifying visages that turned those who beheld them to stone. Traditionally, two of the Gorgons, Stheno and Euryale, were immortal, but their sister Medusa was not and was slain by the demigod and hero Perseus.
Gorgons were a popular image in Greek mythology, appearing in the earliest of written records of Ancient Greek religious beliefs such as those of Homer, which may date to as early as 1194–1184 BC. Because of their legendary and powerful gaze that could turn one to stone, images of the Gorgons were put upon objects and buildings for protection.