Leafy sea dragon
The leafy sea dragon, which lives off the coasts of east and south Australia, is closely related to seahorses and pipefish. However, these guys will make you give a double take since they resemble seaweed rather than fish.
Male and female quetzals have the same vibrant colors, but only the males develop the train of twin feathers. During mating season, these trains can grow up to three feet long in order to attract females.