Enchelei

From Ancient Greek Ἐγχέλιοι (Enkhélioi), from ἔγχελυς (énkhelus, “eel”). Possibly from the Illyrian cognate of the word, itself closely related to Albanian ngjalë (“eel”). This is made further plausible by the word being found with a -γγ- (-ng-) in place of -γχ- (-nkh-) in Mnaseas. The demonym can be traced back to mythology, where Cadmus, become king of this people, turns into a serpent.

来源：wiktionary