As of May 1, 2014, the largest catfish ever caught was a 646-pound catfish caught in the Mekong River in Northern Thailand. The fish was approximately 9 feet long and the size of a grizzly bear.
This species of fish is the Mekong giant catfish, which may also be the largest freshwater fish ever recorded, according to National Geographic. Catfish are bottom-feeding fish that can be found on nearly any continent in the world with the exception of Antarctica. These fish are easily identified due to their flat heads and long protruding facial whiskers, which are used for smelling what they are about to eat.