The humphead parrotfish, Bolbometopon muricatum, is the largest species of parrotfish. Its jaws are so strong that it can bite through rock. Humphead parrotfish are like bulldozers on reefs. They swim along chomping through corals and pooping it out as fine white sand- tons of it, enough to form tropical beaches!
Watch the video below to learn more:
Sea hares, on the other hand, are more like lawnmowers. They munch down on algae constantly.