Which goldfishes are freaks?

The wild goldfish is a very common fish from China, usually green or brown in colour. About a thousands years ago the Chinese noticed that red forms of the wild goldfish occasionally appeared. They started to keep these more attractive forms in ponds and bowls and managed to breed them. Since then goldfishes have always been popular as pets and many different varieties and forms have been produced. Some of these are so bizarre they barely resemble fishes at all. The Lion head Goldfish for example, has a large head grossly.