Hagfish are really
weird fish. They live in the deep sea, and are covered with slime. There are actually about 30 species of hagfish; they are of the class of
Agnatha, the order
Myxini, and the family
Myxinidae.
Hagfish are tan in color and look much like eels. Around their mouth are 8 feelers used for smelling; the mouth itself is a primitive hole. Hagfish have no bones or complex internal organs, and their bodies are composed of a strip of cartilage surrounded by muscle.
They're slimy. They exude slime. They often have to twist themselves into knots just to get rid of all the slime. They also twist in knots to constrict their prey (dying fish) while they suck out its guts.