bullhead

noun

1. any of several North American, freshwater catfishes of the genus Ictalurus, having a rounded or truncate caudal fin.
2. 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 head.
3. an obstinate or stupid person.

noun

1. any of various small northern mainly marine scorpaenoid fishes of the family Cottidae that have a large head covered with bony plates and spines
2. any freshwater North American catfish of the genus Ameiurus (or Ictalurus), having a large head bearing several long barbels
3. a scorpion fish, Scorpaena guttata, of North American Pacific coastal waters
4. informal a stupidly stubborn or unintelligent person