Euglena sp. in pond water, moving in a rotating motion using its flagellum. Rod-shaped bacteria appear in the background. Euglena is a single-celled plant-like protist with an oozing, ever-changing shape. Its bright green colour comes from chloroplasts used in photosynthesis. It propels itself with a single, hair-like flagellum located at its leading end. It is attracted to light and finds its way using the red eyespot located near the base of its flagellum. Euglena lives in ponds and puddles, creating starch in sunlight and feeding off large organic molecules in the dark.