The lingcod or ling cod (Ophiodon elongatus) is a fish of the greenling family Hexagrammidae. Despite its name, the lingcod is neither a cod nor a ling. It is also known as the buffalo cod, cultus cod, or Buckethead. It is the only extant member of the genus Ophiodon. A slightly larger, extinct species, Ophiodon ozymandias, is known from fossils from the Late Miocene of Southern California.
Ophiodon elongatus is native to the North American west coast from Shumagin Islands in the Gulf of Alaska to Baja California, Mexico. It has been observed up to a size of 152 centimetres (60 in) and a confirmed weight of 39 kilograms (86 lb), with unconfirmed reports of fish weighing more than 50 kilograms (110 lb). It is spotted in various shades of gray. The lingcod is a popular eating fish and is thus prized by anglers. Though not closely related to either ling or cod, the name "lingcod" originated because it somewhat resembles those fish. Around 20% of lingcods have blue green to turquoise flesh.p. 298 The color, which is no longer present after cooking, may be due to biliverdin, but this has not been established beyond doubt.