The zigzag eel, also known as the tire track eel (Mastacembelus armatus), is a species of ray-finned fish that belongs to the Mastacembelidae family. These ray-finned fish are native to the riverine fauna of Pakistan, Sri Lanka, Sumatra, Thailand, Vietnam, India and other regions of Southeast Asia.
Zigzag eels are nocturnal predators that do best in still waters, lowland wetlands, highland streams, coastal marshes, and rivers with rocky or sandy river beds and thick vegetation. The back of the zigzag eel is dark beige in color, and it has a silver-beige head. It has an elongated, snake-like body and a dorsal fin that is preceded by a number of spines.