The old man fish, also known as toadfish, monkfish, ugly woman and so on. Fish order, anglerfish order, anglerfish family, soft body, no scales, the head and the edge of the body has many cortical protrusions. The anterior half of the body is flat and disc-shaped, with a tiny tail. The body length is more than 50 centimeters. Dorsum purple-brown, ventral surface light color. Head large, mouth wide, teeth sharp, black and white markings inside mouth. Pectoral fins broad and brachycephalic. The foremost three fin spines of the dorsal fin are separated, and the tip of the first spine has a cortical flap (also called a cortical spike), and the flap is parasitized with some luminous bacteria, like a fishing rod hanging a bright light. In addition, the old man fish is also the common name for the Ge's perch pond snakehead of the order Perciformes, family Pangasidae.

Because of its small size and living in swampy bubbling marshes, it usually has parasites in the head when eating it must be removed from the head, and its meat is tender, with few thorns and flavorful, nutritious, and has a high food value.