The Oranda Goldfish is one of the most popular goldfish in the world. It is favoured for its hood, a fleshy growth on the top of its head called the wen. The wen starts to show at about 3 - 4 months, but only really begins to form at about 1 - 2 years. The hood is fully developed when the fish gets to be about 2-2 1/2 years old. The Oranda Goldfish in the picture is too young to have a well developed hood.