One of the first beings to come into existence, Gaia represents and IS the very earth. She has a rather complicated relationship with her direct descendants (specifically Uranus, Kronos, and Zeus), as she helps them rise to power only to turn against them soon after.
Gaia
One of the first beings to come into existence, Tartarus represents and IS the stormy hellish pit far below the earth. He is most often used in myth to contain dangerous beings, a few of which he fathered.
An ancient sea-god and -goddess of the dangers of the deep, Phorcys and Ceto were the parents of several other monsters, such as the Gorgons, the Graeae, Scylla, and Echidna, the latter of which went on to have several monstrous offspring of her own.
The 'father of all monsters' of Greek mythology, Typhon attempted to kill Zeus to avenge his defeated Titan brothers, but was himself defeated and buried under Mount Etna... which made it one of the world's most active volcano.
The 'mother of all monsters' of Greek mythology, Echidna was herself from a family of monsters that included the Gorgons. With Typhon, she gave birth to infamous beast such as the Chimera, Cerberus, Sphinx, and Hydra.
