Hagfish

Hagfish, any of a family (Myxinidae) of predatory marine fishes related to the lamprey. They resemble eels and have circular mouths ringed by tentacles. Their tongues have sharp teeth, and they feed on worms, crustaceans, and fish located by smell. Hagfish grow to just over 2 ft (61 cm) long and are found in seas around the world on soft mud in fairly deep water. If a hagfish is roughly handled, it secretes a large quantity of shiny mucus, for which it is sometimes called the slime eel.