Golden Carp

The Golden Carp is a very rare Fish caught from bodies of water Underground, in the Cavern, and in Hell. It currently has no use, but at is much more valuable than most fish, and so can be good for making money.

Trivia
Could be a reference to NateWantsToBattle and Dookieshed on Youtube, who made up the KHRP (Carp) joke for Magikarp, and the SHINY GOLDEN KHRP joke for Shiny Magikarp. The Golden Carp's description says that it is shiny, meaning it most likely is a reference to them.