sea devil

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A devil ray or the manta.
• noun An anglerfish.

from the GNU version of the Collaborative International Dictionary of English.

• Any very large ray, especially any species of the genus Manta or Cephaloptera, some of which become more than twenty feet across and weigh several tons. See also Ox ray, under ox.
• Any large cephalopod, as a large Octopus, or a giant squid (Architeuthis). See devilfish.
• The angler.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any very large ray, especially any species of the genus Manta or Cephaloptera.
• noun Any large cephalopod.
• noun The angler.