The Telkhines were magical sea smiths, and sea daimones that were native to the islands of Keos and Rhodes. In a fragment of Stesichorus' they are also described as being death spirits and darkeners. Depending on the account there are either four or nine of them. Differnt texts give them differnt names: Aktaios, Argyron, Atabyrius, Damnameneus, Damon or Damonax, Hormenus, Lykos or Lyktos, Megalesios, Mylas, Nicon, Ormenos, Simon,and Skelmis. Their children Dexithea, Lysagora, and Makelo were also Telkhines but were female instead of male. It is unknow which of the orginal are their father(s) and some texts refer to Makelo being the mother of Dexithea, her sister, or even both. It is also strongly implied that there are more of the sisters, they just are not given names. Their parents are Pontus and Gaia, the blood of Ouranos and Gaia, Tartaros and Nemisis, Thalassa, or Poseidon. They are described as having the flippers and tails like fish, the face of a dog, and the torso of a human
They occasionally appear in myths as helpers to others, usually in earlier stories. In Strabo's Geography it is said that Rhea accompanied the Telkihines on a journey from Krete to their island of Rhodes and gave them Zeus to raise (though it is believed that they were actually being confused with the Kuretes who were also daimons that did metalwork), while Library of History says that they along with Kapheira (daughter of Okeanus) were given the baby Poseidon from Rhea in order to raise.
They are said to have been the creators of the art of metal working and created weapons such as the sythe used to castrate Kronos, Poseidon's magical trident which gave him the power to level mountains into the seas and form new islans, and helped Hephaestus craft the Necklace of Harmonia. They also taught men the art of creating statues of the gods. In addition to that they were skilled sorcerers who were able to summon clouds, rain, hail, and snow, and were able to shape shift. These powers though they gaurded jealously an wouldn't teach to outsiders.
Eventually they began to use their posers for evil and the gods decided to destroy them. Depending on the text either Zeus threw them into Tartaros or struck them all with lightning, Poseidon drowned them in a flood or used his trident to destroy their island and cast them below the sea, or Apollo shape shifted into a wolf and destroyed them. In Nonnus' Dionysiaca they grew angry at the Heliadae (seafears and astrologers) who brought the Athenians to their island of Rhodes and who eventually drove them out. As revenge they decided to kill all the plants and animals by mixing water from the river Styx with sulfar. Though the female Telkhines were said to be spared, mostly due to the fact that Makelo entertained both Zeus and Poseidon, or that due to her being in their favor that only she survived while the others perished.