Earthborn Kings
The following earth-born kings were the early rulers of Attica and Athens. They were mythical beings: part man and part serpent.
Cecrops was the first such king. It was during this time that Poseidon and Athena contested for the patronage of Athens.
Erichthonius was also part man and part serpent. Erichthonius was the son of Hephaestus and Gaea. Hephaestus wanted to marry Athena, the virgin war goddess. When Hephaestus tried to ravish Athena, the goddess managed to ward him off, causing Hephaestus' semen to fall on earth, from which Erichthonius was born.
Athena entrusted Cecrops' daughters (Aglauros, Pandrosos and Herse) to guard a chest, warning them not to open the box. Their curiosity of what was in the box brought about their madness and death, since they couldn't resist opening the box. What they discovered was the infant Erichthonius. Madness overcame the daughters of Cecrops; they ran off a cliff and fell to their death.
Athena then reared Erichthonius until he was old enough to become king of Athens.
There were other earth-born kings such as Lelex and Pelasgus (Pelasgos), who ruled in Argos, Arcadia and Messenia. Apollodorus also reported that he might be the son of Zeus and Niobe, and brother of Argus, king of Argos.
It doesn't say anything about Pelasgus or Lelex having a tail of serpent. They were born from the earth.
By Jimmy Joe