It’s a fish.

Eels are fish. In taxonomy, eels belong to the class Fish, subclass Actinopterygii, order Synbranchidae, and family Synbranchidae. It looks like a snake, but that doesn't affect its identity as a fish. Eels mainly live in the intersection zone of salt water and fresh water, and like to live in unpolluted waters. Eel is a fish with high nutritional value and is usually eaten. The nutritional value of eel also includes medicinal effects such as anti-inflammatory, disinfection, blood replenishing, qi replenishing, and rheumatism removal.