There’s its diet, which consists primarily of algae taken from pieces coral ripped from a reef with their tusk-like teeth that are fused together forming a beak, hence the “parrot fish”. The coral is ground down with their teeth in the fishes’ throats and made into sand. Much of the sand in the parrot fish’s range is actually the ground-up, undigested coral they excrete. There’s its gender, which they can change repeatedly throughout their lives, and their coloration and patterns, which are absolutely amazing and vary greatly, even between the males, females, and juveniles of the same species.
Finally, there are the pajamas. Every night, certain species of parrot fish envelope themselves in a transparent cocoon made of mucous secreted from an organ on their head. Scientists think the cocoon masks their scent, making them harder for nocturnal predators, like moray eels, to find.