Golden Carp

Golden Carp are a type of fish which are found extremely rarely by fishing in any biome on the Underground, Cavern and Underworld layers, with the exception of the Desert /  an Ice biome that is Corrupted, Crimsoned, or Hallowed. Unlike most other fish, Golden Carp are not used for crafting. Instead, they have a pretty dang high sell value of.

Trivia

 * Despite being a golden fish, they are unable to be used to craft the or any type of.