Hagfish, a jawless, eel-shaped scavenger fish living on muddy ocean bottoms in temperate waters. A hagfish grows to a length of about two feet (61 cm). It has a sucker mouth, which is surrounded by four to six barbels (fleshy tentacles), and it has teeth on its tongue. A slimy substance on its body helps a hagfish slip away from predators. Hagfish eat dead fish. They also eat dying fish caught in nets and cause much damage in the coastal fisheries of North America. Hagfish burrow into their prey, devouring the flesh and leaving only skin and bones.

There are more than 30 species of hagfish, belonging to the order Myxiniformes. The common Atlantic hagfish is Myxine glutinosa; the Pacific hagfish, Eptatretus stoutii.