What is "serpent eel"

The serpent eel or sand snake-eel, Ophisurus serpens, is an eel of the genus Ophisurus, found in the eastern Atlantic, western Mediterranean, western Indian Ocean, western Pacific, and the north east coast of North Island in New Zealand. It can be found to depths of about 300 m, on sandy or muddy bottoms near rock outcrops. Its length is between 150 and 250 centimetres.