Telchines

In Greek mythology, the Telchines were the original inhabitants of the island of Rhodes, and were known in Crete and Cyprus. They were excellent metallurgists. By some accounts, their children were the goddesses: Ialysa, Kamira and Linda. The Telchines raised Poseidon. They were associated with the Cyclopes, Dactyls[?] and Curetes.

The gods killed them because they turned into evil wizards.

Alternatively, their were nine Telchines, children of Thalassa and Pontus. They had flippers instead of hands and dogs' heads; they were known as fish children.