- any of several North American, freshwater catfishes of the genus Ictalurus, having a rounded or truncate caudal fin.
- any of several other fishes, as the freshwater sculpins of the genus Cottus, especially those species having a hornlike spine on each side of the .
- an obstinate or stupid person.
- any of various small northern mainly marine scorpaenoid fishes of the family Cottidae that have a large head covered with bony plates and spines
- any freshwater North American catfish of the genus Ameiurus (or Ictalurus), having a large head bearing several long barbels
- a scorpion fish, Scorpaena guttata, of North American Pacific coastal waters
- informal a stupidly stubborn or unintelligent person