The eel is actually a fish, although it doesn't look very fish-like. Its head and body look like a snake, and it has scales―but it is definitely a fish. The face of an eel can be scary, with its sharp teeth and snapping jaws. But when it flaps its mouth open and closed, as though priming itself for an attack, it's actually breathing, not being aggressive. Snorkelers are often scared when they encounter a snapping eel, but there is usually nothing to be afraid of.