Juvenile Harlequin Sweetlips (Plectorhinchus chaetodonoides) escape predation by swimming erratically to mimic the movements of the poisonous flatworm. Their large white spots are believed by some to be an additional deterrent, as they resemble the markings of nudibranchs, which are also toxic to ingest. When they grow to adulthood, their appearance changes dramatically. They become freckled with smaller spots and develop their large namesake lips, which they use to borrow through the sand to eat invertebrates. We saw this little guy while diving Apo Island in Dauin, Philippines. Read more in our post, Pristine Reefs and Macro Critters: Scuba Diving Apo Island, Dauin, and Zamboanguita, Philippines.