The harlequin sweetlips, Plectorhinchus chaetodonoides, a sweetlips of the family Haemulidae, is found in Indo-West Pacific oceans. Its length is up to 72 cm.
Juveniles are brown with large white blotches and mimic the movement of a poisonous flatworm for defence against predators. They gain more spots and the spots reverse from white to black as they age.
It inhabits coral reefs and feeds on crustaceans, mollusks and other fish.