Eels and snakes are similar in size, eels belong to fish, snakes belong to reptiles. The eel belongs to the order of gillfish, gillfish family, eel genus. The body is slender and snake-like, the body is rounded in front and later laterally compressed, and the tail is pointed and thin. The head is long and round. The mouth is large, terminal, with slightly protruding upper jaw and rather developed lips. The upper and lower jaws and the capitulum have fine teeth. Eyes small, covered by a thin skin. The left and right gill pores are united on the ventral surface in a "V" shape. The gill membrane is attached to the gill isthmus. Body surface generally lubricated with fluid to facilitate escape, scale-free. Pectoral and ventral fins are absent; dorsal and anal fins are reduced to mere folds of skin, with no soft spines, all united with the caudal fin. When living, the body is mostly yellowish brown, yellowish or orange-yellow, with dark gray spots, but also a few eels are white, commonly known as "white eel".

Snakes belong to the reptile order Serpentes, elongated, limbs degenerate, body surface covered with scales, although the snake is slender but vertebrates. Mostly terrestrial, but also semi-arboreal, semi-aquatic and aquatic

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