Lingcod are large, up to 5 feet (1.5 meters) long and weighing 100 pounds (45 kilograms). The mouth has large teeth. The dorsal fin runs the entire length of the body and looks like two fins. Most lingcod are brown; some are blue-green. They all have staggered black blotches along the sides of the body and the back. Males become all black in the winter just before mating.