An oranda is a breed of goldfish characterized by a prominent bubble-like "hood" on the head. The headgrowth or hood also known as wen or crown may be a prominent growth on the top of the head cranial region or may encase the entire face except for the eyes and mouth. Due to the fleshy outgrowth on the upper half of its head and sides of its face, the oranda has become one of the most popular goldfish. The headgrowth is described as a "wen" by Chinese aquarists. The mass is benign  and comes from selective breeding.
The Redcap Oranda Goldfish is the most popular ornamental fish among the aquarium enthusiasts due to their egg shaped body and brilliant coloration. It belongs to the family Cyprinidae under order Cypriniformes of class Actinopterygii. Oranda goldfish was originated in the late s by crossing between a lionhead and Japanese Fantail goldfish.