Scientists have documented a novel protozoan species, Euplotes gigatrox, discovered in a seawater filtration system in Curaçao, that undergoes a remarkable transformation into a "supergiant" form. These single-celled organisms, normally filter-feeders of bacteria, can more than double in length, develop a larger mouth, and become predatory cannibals, hunting and consuming their own kind at a rate of about one prey every ten minutes. This "supergiant" stage exhibits altered movement patterns, better suited for hunting. Genetic analysis reveals distinct developmental stages with widespread differences in gene activity, and cells reverting from the supergiant state possess molecules that temporarily inhibit re-transformation. This discovery challenges traditional views of developmental biology, primarily focused on multicellular animals, by offering a single-celled model to study complex cellular development and behavior.