Marble relief from Aphrodisias, in Caria (modern Turkey), dating to the Roman period (II century A.D.), now in the Archaeological Museums (Arkeoloji Müzeleri), Istanbul, Turkey. The image shows the goddess Athena fighting against the Giants. These were creatures of much greater size than humans, who were born from the blood drops of Uranus (progenitor of the Titans, the primordial beings) which were fallen on the Earth when he was emasculated by his son, Cronus (Zeus’s father). The Giants were thus children of the Earth and, instigated by their mother, made an assault on the Olympus, but were defeated from the gods after a dreadful fight. In the iconography, the Giants are frequently represented as wild men, wearing animal skins, armed with rocks and tree trunks, or as hybrid creatures, with the lower part of their bodies in the shape of serpents (Kerényi 1951, p. 34).

[Source: http://ancientrome.ru/art/artworken/img.htm?id=3795]