Long base dorsal fin, originating above or slightly in front of anal fin origin. Caudal fin forked.
Pectoral fins high on the body with round margin.
Pelvic fins close together and broadly attached to the body. Broad jaws with lower jaw distinctly projecting. Villiform teeth with several large canine-like teeth. Small cycloid scales deeply embedded in the skin. This species clings to marine mammals, mainly cetaceans, using its sucking disk.